Sidonia no Kishi Wiki

Nagate Tanikaze (谷風長道, Tanikaze Nagate) is the series' main protagonist. He is the clone of Hiroki Saitou, but was secretly raised as his grandson and trained all his life to become an ace pilot in the underground of Sidonia. After the death of Hiroki, Nagate ventured out to the surface and was adopted by Kobayashi; she made special arrangements for Nagate to pilot Hiroki's Tsugumori and he quickly became the top ace Gardes pilot. At the end of the Fifth Gauna War, he married Tsumugi Shiraui and settled in Lem VII, where they had a daughter named Nodoka.

Character & Personality

Nagate was raised by his grandfather, Hiroki Saitou. Unknown to Nagate, he is Hiroki's clone. Created to give Hiroki a young immortal body, Hiroki didn't want his clone to suffer a cruel fate and hidden him underground. Hiroki would raise Nagate to be a skilled gardes pilot against the Gauna. Due to his enhanced body, Nagate has a high metabolism that causes him to hunger easily and eats often. A compulsive eater, he's easily motivated by the prospect of food; his hunger is an irritating-but-amusing matter to his friends as he wasn't genetically engineered to photosynthesize. He only looses his appetite when he feels down or depressed about something.

Nagate enjoying the taste.

After Hiroki died, Nagate ventured out to Sidonia's surface and was forced to adapt to society. Because of Nagate's lack of contact with humanity, he is naïve to common social practices. Poor in socializing, he's often placed in awkward situations and got into a few violent encounters with people around him. However, he proved to be a good friend to others, always putting himself at risk to protect those he cares about. He is also very driven in gardes combat since Hiroki always taught him to press on since the enemy will not be merciful towards him.

The legacy of Hiroki has been a mixed blessing. Those who do not know the true nature of Nagate often treat him unfairly. However, those that know he is Hiroki's clone gave him special treatment. Kobayashi's love for Hiroki motivated her to adopt Nagate and shown great faith that he will make it through to become the next ace pilot. Lala's deep friendship with Hiroki motivates her to care for Nagate as a doting mother; Nagate always appreciated her kindness towards him, not even realizing her reasons. Nagate's ace pilot status and kind nature also earned him a following of women who are devoted and protective of him.

Nagate and Hoshijiro connection.

Because of his lack of understanding of women, Nagate is not aware that there are many girls interested in him. Izana, Shizuka, Honoka, Yuhata Samari, and Tsumugi all displayed attraction towards him but he never realized it. This has created a lot of awkward situations with them usually making them mad at him and leaving him baffled what he did. However, he grew close to Shizuka Hoshijiro and formed a romantic relationship with her. Unfortunately, she was killed in combat and it haunted Nagate.

Nagate and Tsumugi connection.

Devoured by a Gauna (GA-487), Nagate blamed himself for her death; it affected his confidence. Even after he redeemed himself on the battlefield and realizing it was Norio's fault, the Gauna continued to haunt Nagate. To psychologically mess with him, the Gauna would imitate the form of the fallen, including Shizuka's likeness. While he continues to feel uncomfortable by the Gauna's tactics, he always had the resolve to defend Sidonia. However, the fact that he later got romantically involved with Tsumugi Shiraui (a chimera born from Shizuka's genetic material) suggests he couldn't get over Shizuka.

Nagate and his friends holding hands-superstition.

More recently, Nagate became more involved in the development of Sidonia. He is now part of a new secret committee (after the Immortal Committee was wiped out), which is strongly dedicated toward the development of war technologies. Because of this, he is heavily involved in the future development of Gardes technology with Toha Heavy Industries and high-priority missions that threaten Sidonia. Overall, his fate is heavily involved with Sidonia as the survival of the ship is the key to his survival and happiness.

Skills & Abilities

File:Nagate thrust GA-487's core with Kabizashi.png

Nagate (Tsugumori) destroying the GA-487's core with a Kabizashi.

  • Sidonia Ace Pilot: Trained since he was little, Nagate trained every day in simulators and managed to exceed Hiroki's performance by age 6. When piloting Tsugumori, Nagate always out-performs his fellow pilots, often getting the most Gauna kills. However, his performance is hindered when working on the Type 18 as he was used to Tsugumori the most. As he becomes the top ace pilot of Sidonia, Nagate gained special access to all prototype gardes units created by Toha Heavy Industries. Because of his skills and high compatibility with Tsumugi Shiraui, their parameters exceed expectations and often paired together to guarantee success in their missions.
  • Immortal: Created as an advanced clone of Hiroki Saitou by Yure Shinatose, Nagate is the only naturally born immortal of Sidonia; he doesn't need a drug regiment to keep himself young. He has a healing factor that allows him to regenerate from extreme injuries in a short time; he can still die from extreme trauma. His advanced healing is due to his high metabolism, but it also causes him to be hungry often and high calorie intake. Considered classified, Kobayashi ordered Nagate keep his regenerative abilities a secret to avoid scrutiny. Nagate has acquired a lot of serious injuries and quickly recovered, including (but not limited to) a broken neck, a severe concussion, a broken hand, a crushed nose, regrow damaged teeth, a dislocated arm, self-resuscitated from a heart failure, and healed from broken leg in a very short time.
  • Tech Savvy: While he was being raised by Hiroki, Nagase gained some experience fixing machines and learning about various simulators fighting technologies that he trained in. It has often instantly recognized the technology around what was supposed to be new prototypes. The first time it has already found a Gauna with a biological Heigus Particle Cannon in combat, he quickly recognized the cannon and its weak point, shooting him with his own gun Heigus in place and exact time needed to cause an explosion Heigus, instantly exposing its true body which he then destroyed with a Kabizashi. His technical insights often impresses people around him.
  • Attractiveness: While not a Casanova, it is remarkable that Nagate seems to exert an irresistible attraction to nearly all his female classmates. With no effort, he always engages in compromising situations with them, indecent exposure, and unintended romantic conditions. He managed to catch a lot of the women half-naked or completely naked throughout the series and end up injured as a result of the awkward situations.


For being clone of Saito, Nagate is physically identical to him in his younger days. He has short black hair that hangs loosely from his head and black eyes on the sleeve (gray in the anime). He is considered beautiful and attractive by most girls in the series, including non-human as Tsumugi or Teruru. He dresses only in uniform or in his old space suit. It does not have a wardrobe; Kobayashi possibly supplying it with fresh clothes for school and in civilian life.


Note: Certain events played out differently in between the manga and the anime; the descriptions below is based on the manga.

Origins & Hiroki's Legacy

Nagate's Embryo raised on Artificial Womb by Kobayashi and Yure

Nagate is an immortal clone of Hiroki Saitou, a legendary ace pilot and a limited immortal. In the aftermath of Ochiai's Insurrection and end of the Fourth Gauna Defense War (year 904 Sidonia Era), Hiroki had a falling-out with the Immortal Ship Committee (specifically Kobayashi) and vanished for 80 years; he later resurfaced (20 years before main events) due to his failing health. He was rescued and privately treated by Kobayashi's team; the prognosis wasn't well. Since he didn't take his immortal medication, Hiroki aged into a frail old man and the only way to save him was to transfer his mind to a younger body. Unfortunately, there were no available clones for Hiroki to substitute. Behind the council's back and without Hiroki's knowledge, Kobayashi had Yure Shinatose create a new clone, genetically modified to be immortal.

Hiroki somehow found out about the clone and broke into the lab to recover his infant copy. Kobayashi lead a small squad (along with Lala) to stop Hiroki from taking the immortal clone. Despite being old, Hiroki still put up a fight and Lala fought against Kobayashi's men to allow Hiroki to escape. It would be the last time anyone saw Hiroki alive. Eventually, Hiroki found a hidden place where he could settle down and named his clone, Nagate.  

Nagate was raised to believe Hiroki is his grandfather, never once revealing his clone origins nor immortal body. Since an infant, Nagate lived with his grandfather and never explored the surface. Making use of the underground resources and abandoned technologies, Hiroki and Nagate survived by repairing damaged items and trashed materials to maintain their underground lifestyle. Hiroki managed to salvage an advanced Gardes 17 Combat Simulator and had Nagate train through it, eventually beating Hiroki's top score by age six.

Hiroki's Death & Discovering Sidonia

Hiroki warning

Approximately 17 years later, Hiroki died of old age and Nagate allowed Hiroki's body to mummify in their quarters for the next three years. Nagate lived his entire life underground with Hiroki; prohibited from going to the surface. However, Nagate completely ran out of food and began starving. Heading through a tunnel, Nagate would acquire food through the right 8th Food Warehouse passage, but he decided to traverse through the left forbidden path (noted by Hiroki). To his surprise, he came right out of a rice processing plant and fell into a packaging machine.

Nagate infiltrate Food Production Facility

When he recovered from falling through the conveyer belt, he broke is left pinky and ring finger, but proceeded to pack away the rice. It was there an employee found him stealing rice and his first encounter with another person other than Hiroki. Fearing he would be composted for theft, he ran for his life and hitched a ride on a rail before thrown out of the window. Surviving his two story fall, he realized he's at a residential area. Just so happens, Norio Kunato and Shizuka Hoshijiro happened to be there and saw the worker, identifying Nagate as a thief. Norio knocked him out and sent him to the police station.

At the interview room, Nagate explained everything to the police, but nobody believed Nagate's story nor could prove his existence (all Sidonians are registered in a database). According to the database, Hiroki was registered deceased 17 years prior and Nagate's identity doesn't exist; the police believes he's not truthful. Before he could explain any further, Nagate collapsed from hunger and sent to the hospital; he would wake up to discover his future.

Kobayashi's Adoption & Joining SDF Academy

At the hospital, Nagate awakened to see Ochiai's clone (Kobayashi's assistant). Nagate has passed out after two days of no food and Ochiai pointed it must be troublesome not to be able to photosynthesize; Nagate remarked he doesn't have an organic convertor reactor inside of him. Ochiai confirmed Nagate's health is in good standing (despite the injuries) and joked it will be a long time before Nagate is turned into fertilizer. He tells Nagate that a benefactor has come forward to vouch for his identity; Ochiai is here to bring Nagate to see Kobayashi. After Ochiai got some Sansai (mountain vegetables) with Nagate, they headed to the elevator and the two formally made introductions.

Kobayashi adopts Nagate

At the top of the highest point of the residential area, Ochiai instructed Nagate to go through a corridor to meet Kobayashi (unmasked), the 28th Captain and Supreme Commander of Sidonia. Unknown to Nagate, Kobayashi had a close friendship with Hiroki; she accepted guardianship over Nagate because of him. It was there she revealed the entirety of Sidonia and she asked for Nagate's help to protect it. Moved by it's beauty and splendor, Nagate pledged to protect Sodonia from the Gauna threat.

Not long after, Kobayashi made arrangements for Nagate to immediately join the Sidonia Defense Force Academy. At the academic dorms, Nagate would meet Lala Hiyama, Hiroki's best friend and den mother to the dormitory students. Although she recognized Nagate as Hiroki's clone, she never introduced herself as Hiroki's old friend; she approached him as a new cadet. Lala showed Nagate his dorm and gave him fresh clothes (his old ones stink). Baffled to see a walking talking bear, Lala actually thought Nagate was staring at her prosthetic arm and explained she had a serious (Gauna) injury as a child.

While exploring around the academy, Nagate bumped into Shizuka and she tried to hide him from trouble. However, a senior officer caught Nagate roaming around the halls without a safety belt. The officer was surprised to find out Nagate doesn't know anything about the importance of safety belts and had him perform a Safety Handrail Durability Test on all the rails as a safety lesson. Tired from the mundanity of the job, Nagate didn't realized he waltzed right into the female photosynthesis room. Surprised at the naked girls, one of the Honoka sisters elbows him, breaking his nose and knocking him out cold while dangling on his safety belt. Later at class, he formally introduces himself to his classmates (to their shock) with his patched nose and grumbling stomach.

Nagate at Military Academy of Sidonia

Sidonia sensors discovered a Samghata Ship (giant Gauna) within their proximity. Kobayashi appears before a SDF assembly and announced a Samghata Ship has appeared in their high-security sector and a threat to Sidonia. Because it has not made any a direct movements, it's unclear will it simply pass by Sidonia. Kobayashi makes it clear that the Gauna can't be communicated with and the only way humanity can survive is through using resolute force. Because Kobayashi is masked, nobody knows how she looks like except for Nagate.

While sitting on the window edge for lunch, one of Nagate's classmates shoved him off the floor with a broom. Because everyone else can photosynthesize, people don't eat as much and produce less body odor. Unfortunately, Nagate eats often; the classmate shoved him off because of his odor and told him to stop eating. While opening his locker, he finds a giant bag of deodorizer and his classmate disgusted at his scent passing by. Despite the passive aggressive behavior and bullying, Nagate quietly puts up with it.

While heading to the dorms, Izana Shinatose approaches Nagate with a case he dropped. Giving it back to Nagate, Nagate feels relieved as it belongs to Lala. Izana suggested a shortcut for Nagate to head back to the dorms, it was while walking together that they made formal introductions. Izana pointed out Nagate is a big eater; Lala is happy to know someone that understands her situation (Lala can't photosynthesize). Curious about Nagate, Izana wondered is Nagate gifted because he was fast-tracked into the SDF. Izana thought if there was a correlation between Nagate and the Gauna as Kobayashi spoke about the outbreak of war when Nagate appeared.

As they walked, Nagate couldn't figure out if Izana was a guy or girl. Seeing Nagate's troubled expression, Izana explained they are neither boy or girl. Izana belongs to a group of people that starts out as non-binary, but will adapt into the opposite sex of their partner for procreation. Even without a partner, it's possible to produce clones through asexual reproduction. The explanation awkwardly satisfied Nagate's curiosity.

The two made it to observe the 18th Style Guardian Virtual Training Facility. Curious to see there are newer machines than Tsugumori, Nagate went to check out the simulator. As the simulator started, Norio, Shizuka, and the Honoka Sisters observed him as they wanted to know his piloting skills. Unfortunately, Nagate performed poorly (unranked) as he's not used to the Type-18 control system. Later, Izana and Nagate went to a Soba restaurant to eat noodles and later returned to school. While cleaning, Izana informed Nagate they're going to sortie on a mining mission; Izana wanted to shake hands before it happens. Confused for its purpose, Izana explained (while shaking hands) there's a superstition that if a pilot would to assemble in a clasp position without touching before, it will lead to accidents. Izana saw Eiko Yamano and asked her to join in, but she felt the superstition is juvenile. Not long, Nagate and Izana got their sortie call.

First Sortie & 5th Gauna War Begins

Nagate chosen as Tsugumori Pilot

Heading to his school locker, he found an air purifier (another prank) lying inside. Izana corrected him to the pilot locker room to put on his skinsuit for the first time. Because Nagate never used this smart suit, Izana had to warn Nagate about the urinary catheter and its dangers. As soon as Nagate finished suiting up and activated his suit, he paused from the discomforting feeling of the catheter attaching itself to him. Not used to traversing in zero gravity, Izana had to show Nagate how to traverse through non-gravity halls using the rails.

At Lane #5, Nagate would suprisingly meet Tsugumori as his gardes. Kobayashi secretly removed Tsugumori from its memorial spot and had engineers make it combat ready once again. Since Nagate trained from a Type-17 Gardes and inherited Hiroki's abilities, Kobayashi believes Nagate is the only person to pilot Tsugumori. Before boarding, Sasaki remarked to Nagate that the Tsugumori is a fine machine and a waste on a newbie like Nagate; she expects the unit to be taken care of or she'll (seriously) punch him out. The engineer assured Tsugumori is just as capable of the Type-18 units.

The squadron of eight are split into two groups: Team Kunato and Team Hoshijiro (top ranked gardes pilots). Norio leads Eiko Yamano, Izana Shinatose, and Nagate. Shizuka leads En Honoka, Ren Honoka, and Hou Honoka. Before launching, Ichirou Seii informs them of their mission: "The ice mining mission begins at 1100. this is not a battle sortie, but a mission to secure vital resources." Nagate launches and joins his team in a quad hand formation; Hoshijiro was mindful to remark that it's Nagate's first sortie for the group to pace him. The team successfully joined hands and thrusted over to the asteroid.

At the asteroid, Eiko and Nagate just activated the electro cutters to mine the ice when it accidentally awakens a dormant Gauna (GA-487) under the surface, officially breaking the 100 years of peace for Sidonia. GA-487 attacked the mining crew. In the first minutes of the surprise attack, Nagate was hit hard on the floor; his neck was injured, broken right leg, and his heart flatlined. Eiko's gardes was destroyed and GA-487 removed her out of the cockpit. The gauna ripped her suit apart, ate her alive, and assimilated into its body. The rest of the pilots scrambled to fight off GA-487's tentacles when Kobayashi commanded Sidonia to fire its Heavy-Mass Cannon; all crafts have been called back to Sidonia. Izana didn't want to leave Nagate behind and tried to retrieve him but got her unit's head cannon knocked off. Just as GA-487 was about to attack Nagate, his regenerative abilities resuscitated himself and jumped immediately into combat.

GA-487 has now taken Eiko's form, a giant naked Eiko with many tentacles. Ichirou Seii tried to call Nagate to retreat, but Nagate engaged GA-487 in close quarters combat (CQC). Tsugumori fought GA-487 by wrestling with it while using its forearm blades to cut the gauna. Nagate launched explosive rods into GA-487 and detonated it, revealing its true body. However, Ichirou insisted Nagate to retreat as the placenta will regenerate and he didn't have a kabi spear to defeat it. Nagate extended it's forearm rod and jammed it through GA-487's mouth and continued wrestling with it until Tsugumori was thrown to the ground. Hoshijiro grabbed Tsugumori to form a seven clasp position to retreat back to Sidonia just seconds away before the heavy-mass cannon shell impacted on the asteroid. The explosion greatly reduced GA-487's mass, but it survived and adrift in space.

Eiko's Funeral & PTSD Aftermath

Nagate at Eiko's funeral

In the aftermath of the encounter, a funeral was held for Eiko and her classmates mourned for her. Still injured from the battle, Ochiai (clone) helped Nagate make it to the funeral to send of Eiko. Upon seeing the memorial plaque, Nagate suffered an anxiety attack and collapsed. While unconscious, Nagate had a grotesques nightmare of what happened. Nagate saw an assimilated Eiko telling him to set up the cutting tool, but the scene switches to a voice(s) that tells him to help Eiko and then suggests it's better to kill her. A giant foot steps on Eiko but she couldn't be squashed. Nagate then hears Ichirou calling for him to retreat and the heavy mass cannon shell squishes Eiko like a bug and Nagate awakens. Nagate wakes up to find himself lying on Izana's leg with vomit on his clothes and Izana's left thigh. Izana reminded Nagate what happened and realized what he had done; he felt guilty that Izana was unable to join the rest of their classmates in the funeral service to send Eiko to the Organic Convertor Reactor. However, Izana wasn't upset and the two watched Eiko's funeral from afar.

Nagate nightmare

Back at the academy, Nagate remains haunted by what happened. He went to the bathroom to vomit again and collapsed to the floor. Nagate awakened to find himself resting at the medical bay, shocked to realize the captain is tending to him. Disguised as a nurse, Kobayashi tended to Nagate and pretended she doesn't know what he's talking about. Nagate realized it's the afternoon and he should be going before classes start. However, he tripped to the ground as soon as he got out of bed. Sitting back on the bed, Nagate wanted to take off his neck brace and leg cast, but Kobayashi excused she doesn't have the authority to do so. Kobayashi tried to get Norio to help escort Nagate, but Norio was preoccupied screwing a classmate and refused to help Nagate; Kobayashi summoned Hoshijiro instead.

As Hoshijiro held up Nagate to walk back to class, he felt embarrassed and was afraid he smelled from the vomiting. However, Hoshijiro didn't notice any stench from him. As they were coming up from the stairs, Izana spotted Nagated and called him (over the Gravity Festival); Izana stormed off after realizing Hoshijiro was holding Nagate. On a Saturday at the dorm, Lala was surprised Nagate was able to walk normally as it hasn't been three days since his bones broke, but his accelerated healing repaired the bone damage. Nagate already feels healed up, but he's still not allowed to take off his cast (to avoid attention over his quick healing). Wondering where everyone went since it's the only day everyone eats, Lala informed Nagate that everyone is attending the Gravity Festival to eat.

Hoshijiro buying food to Nagate

Curious about the festival, Nagate went to catch a meal at a food stall. When the owner asked him to pay, ¥500 (~$4.84 USD) Nagate realized he didn't bring any money. Fortunately, Hoshijiro appeared (in a beautiful kimono) and paid for his meal. While sitting down at a bench, Nagate credited Hoshijiro for pulling him away or the mass-cannon shell would've killed him. Not wanting to focus about the battle, Hoshijiro wanted them both to enjoy the festivities. While enjoying the food, Izana was walking across from the two. She was eating a candied apple and too distracted watching Nagate and Hoshijiro when she bumped into Norio and the skewer punctured Izana's left thigh. Norio was on a date and brushed Izana off, but Nagate saw what happened and shouted for Norio. Feeling high and mighty, Norio didn't want to be addressed in such a familiar manner by inferior people. Angered, Nagate charged at Norio and tried to whack him with his crutch, but Norio took Nagate down and put him in an arm lock. Enraged that Nagate was chosen to pilot Tsugumori over him, Norio twisted Nagate's arm harder until he screamed.

Norio let Nagate go as he's due to appear at the Gravity Cup gardes competition. Hoshijiro helped Nagate get his arm treated and left him with Izana in his dorm. Curious about the gravity cup results, Izana opened the TV to learn Norio lost to Mochikuni Akai, 12th reigning champion. Nagate fell asleep as Izana kept him company; Akai made a surprise appearance to see Nagate. Izana tried to wake Nagate up, but Akai didn't want to disturb him. Akai instead communicated with Izana to invite Nagate and join them on Saturday to a beach outing.

Beach Day with Akai Squad & Decimated Sortie

Upon Saturday morning, Izana and Nagate met up to see Akai Squadron (Izumo Midorikawa, Hinata Momose, Mochikuni Akai, and Kashiwade Aoki), guardians of Sidonia. Izana was packed with camping gear and Nagate awkwardly appeared with his space suit. All of Nagate's clothes were washed and the only thing available was his suit. Heading to Laputa (an island-like destination that only a selective few can access), Izana and Nagate have been given limited access to hang with Akai Squad. Curious over the invitation, Izana explained Akai Squad likely wanted to talk to them about their battle with GA-487. Not many have seen a live gauna and fought one; they want to learn from Nagate's account.

At Laputa, Nagate walked to the edge of the beach to marvel at its splendor. Izana didn't realize Nagate was right below her and she fell right on top of him and the two fell into the water. Akai Squad spared some clothes to Nagate and the team brought a large tuna to prepare a feast. At twilight, Izumo gave toast to their last dinner. Both Nagate and Izana wanted to know what Izumo meant by that; Aoki explained GA-487 is heading towards Sidonia. Akai continued explaining that their squadron has been chosen as the suppression team and two Kabizashis have been prepared; they will sortie tomorrow. Both Nagate and Izana felt like they're intruding on such a personal moment, but Izumo excused his earlier words as a joke. Just suddenly, Nagate collapsed again.

Later at night, Nagate woke up in search of a toilet. While looking, he accidentally overheard Momose wondering is Akai (they're a couple) scared of facing GA-487 as the cuddled over a blanket. Akai reassured Momose that the GA-487 isn't a great threat and he's more afraid of her father; they both hope things will end quickly. The following day, Akai Squad sortied to face GA-487 with disastrous results.

The next day, Akai Squad sortied and stood on Sidonia's top as they prepare to head towards GA-487. With all of Sidonia watching their battle, Akai Squad flew towards GA-487 with Akai taking the lead attack. Unfortunately, the gauna severed his unit's right arm (holding the kabi spear). GA-487 ensnared Akai's unit with its tentacles and breached through his cockpit; Nagate and all of Sidonia watched in shock and disbelief with Akai's headless body during the battle.

Aoki and Izumo attempt another run with Momose being emotionally compromised over Akai's death. As the chased GA-487, it launched its tentacles after them. Izumo managed to fire his particle cannon to reveal its true body, but both Aoki's unit got ensnared and torn apart; all kabi spears are adrift. Kobayashi called for a retreat, but Momose wants revenge for Akai. GA-487 attacked with its tentacles and Izumo used his unit to block the attack for Momose to escape. Unfortunately, Momose's unit was also compromised; Akai Squad is annihilated.

No one has time to mourn as GA-487 continues to fly towards Sidonia. Kobayashi had Sidonia take evasive maneuvers, but to move a massive ship will cause seismic shifts within the ship; an emergency gravity alert was made within Sidonia to have everyone secure themselves. Nagate, Shizuka, and Izana managed to find their own safety spot, but not everyone was lucky. Shizuka tried to help another student secure himself, but he fell to his death. As both thrusters ignited for acceleration, the residential area is being torn apart; structures are ripped apart and people are splattering to their deaths. Sidonia successfully evaded GA-487, but the gauna launched Momose's unit and left it on the rear surface of Sidonia.

Retrieving Kabi Spear & Killing First Gauna

After the incident, the trio started helping the injured and found people dead despite being secured on the rails. Nagate found a stranded live fish, Shizuka told him to prioritize people first when they suddenly got a sortie call. With their best pilots dead, the trainees are all that's left. Ichirou had assembled Norio, Hoshijiro, En, and Nagate as the next four-man team to sortie and recover the kabi spear while the rest of them remain on standby. In their mission briefing, Ichirou tells them they will intercept and retrieve one of the two kabi spears. However, they can't accelerate beyond the range of Sidonia; if they go beyond their range, there will be no rescue as Sidonia will not stop and make a 180 turn for them.

As Nagate's team sortied, they found 256 guardians deployed as part of the defense team in case GA-487 reaches to Sidonia. The team retrieved the spear, but it also drew the attention of GA-487. Ichirou instructed Nagate's team to join hands to outpace GA-487. To everyone's surprise, GA-487 changed its body into a Higgs Particle Cannon; Ichirou had the squad scatter just seconds when GA-487 fired. While there was no direct hit, the proximity of the blast disabled all their units. Hoshijiro's engine lost control and jetted towards the opposite direction of Sidonia. Unable to regain control, the engine was about to blow and Hoshijiro performed an emergency exit.

Nagate survived the blast and Tsugumori is the only operational gardes. As Nagate consider his options, the coms tells him Hoshijiro's condition is unknown, GA-487 is closing in, and HQ wants him to tow Norio and En out of harms way. Nagate realizes GA-487 developed a massive Higgs Particle Cannon and believes he identified an organ that resembles a Higgs delivery tank. Nagate decides to take the kabi spear from Norio and face the gauna. Ichirou questions Nagate's judgement and tells him to stop. The coms warns the gauna is about to fire again; Nagate managed to dodge the particle beam but Tsugumori loses its left arm. Nagate returned beam fire, exposing GA-487's true body. Nagate charges into GA-487 and spears through the Eiko-imitated head, destroying GA-487; all of Sidonia rejoiced in the victory. Ichirou checked on Nagate and he confirmed he's well. However, instead of standing by for orders, Nagate tells HQ to retrieve Norio and En as he intends to rescue Hoshijiro. Before anyone can say anything about it, Tsugumori darts out of range.

Rescuing Hoshijiro & Heroic Return

Ichirou tried to stop Nagate, he warning Nagate it's against ship laws and if he goes beyond the Sidonia's boundary, he won't be able to come back to Sidonia. Nagate acknowledge the situation and apologizes before losing transmission. Taking in consideration of the direction and speed when Hoshijiro left Sidonia's return limit, he made an educated guess she'll be in this area of space. Before he can begin searching, Tsugumori ran low on Higgs particles and now on inertial drift. Fortunately, he spotted Hoshijiro and retrieved her; they're both stranded.

Nagate save Hoshijiro

After Hoshijiro boarded Tsugumori, Nagate apologized as they can't go back to Sidonia. Hoshijiro overheard everything over the coms, she admitted she didn't reply because she didn't want anyone to come after her; Nagate apologized for thinking he could get her in time. Hoshijiro felt Nagate didn't have to apologize nor die after defeating the gauna. Secured back in Tsugumori, the two focused on checking on emergency survival rations and power.

The duo manually opened Tsugumori's Higgs Capture Membrane to recharge the gardes. With nothing to do, Nagate went to sleep. When he awakened, he realized he has been over-drinking his emergency water ration. To his surprise, he awkwardly found Hoshijiro naked from photosynthesizing. Going for more water, he realized there's no more water to dispense despite the sensor saying there should be water left. The two checked on the storage tank and realized it's damaged and they're out of water.

On the 11th day, Hoshijiro wondered about the origins of human carriers and how many are out there. She wondered if they are ships or gauna hives. She reflects there is still very little understand about the gauna since the start of their conflict, believing it's due to no success in communication. She pointed out that the gauna that descended onto Earth had human forms; there was never a case of gauna assimilating a human. She wonders if the gauna are misunderstood, that they're trying to befriend humanity but it wasn't done right because of their differences. Nagate also believes communication would change things but he's losing strength from dehydration. Hoshijiro filters out her urine and feeds it to Nagate to refresh him. After getting his fill, he realizes the unit's lubricant also contains water and believes they can filter it.

Externally accessing the water filtration system, the two managed to filter out a bag's worth of water. In their joy they embraced each other and had a moment when Hoshijiro noticed something. To their surprise, a massive glowing ring appears before them. It's the reverse-thrust of 256 gardes in clasp position. The entire defense team defied ship laws to rescue Nagate and Hoshijiro. Over the coms, HQ wondered how they are going to take responsibility for this. Kobayashi points out they don't have 257 detention rooms; everyone gets a pass over the situation to the defense team's joy. Boarding into Tsuruuchi's gardes, Tsuruuchi offers Nagate a drink but jokes the water isn't from him (a jab on him drinking Hoshijiro's recycled pee) and everyone returns home. Back at the hanger, Nagate finds himself following Hoshijiro and she reminds him the boys room is at another direction. Due to being away for 11 days, both of them had to be scrubbed down and going through quarantine process before heading back home.

Three weeks later, Nagate comes back to SDF Academy and the cadets have a new level of respect for him. When he opened his locker, he found it filled to the top with large bags of 10Kg rice. Izana was surprised to find Nagate here instead of resting, but Nagate didn't have anything to do at the dorms and wanted to come help with the cleaning. Nagate was amazed how things look so normal but Izana points out the organic converter reactor has been running non-stop to process so many dead. The two headed to the memorial plaque to show respects to the fallen, Akai Squad. Just as they were leaving, they found a girl bowing as Nagate passed by, it was Izumo's little sister, Yuhata Midorikawa.

Later at the academy, Nagate would do a historic review about the gauna conflict. From the basics of terminologies, historic accounts of the gauna tearing Earth in half, the Kabizashi, gauna classes, seed ships leaving the solar system, and losing contact with the Aposimz. Nagate stopped review after getting hungry. Later at an assembly, Kobayashi declared Nagate, En, Norio, and Hoshijiro as the new four guardians.

Kunato Squad become Sidonia Defense Force as a official pilot

At the celebration dinner, Izana suggested they go check out the marine level as formal guardians can go anytime. While eating, one of the Honoka sisters congratulates Nagate but figures he can't tell siblings apart. She identifies En who broke his nose earlier for walking into the girl's room. Hou encouraged En to apologize to Nagate, but En didn't think she need to and thought Hou was angry about Nagate seeing her naked. Norio approached Nagate and declared they are now comrades and should forget past transgressions (mostly Norio's prickly attitude). The four agreed to grasp position together to symbolize a fresh start as fellow guardians.

While Nagate was enjoying some tempura with Izana, Yuhata Midorikawa appears and introduces herself to Nagate. Surprised to hear Midorikawa, Yuhata crashed their party to thank Nagate for avenging Izumo (big brother). Yuhata admitted she was formally invited and couldn't get in; she quickly switched topic and wanted to get Nagate a drink. Nagate asked for soup, but Yuhata was confused as she thinks he wants soup to dip into the tempura. Just then, he saw Kobayashi; he dumped his food on Izana and dashed to see her.

Nagate called out to speak with the captain and she cleared it with her guards to ride in the elevator together. Alone in the lift, Kobayashi commended on his work but Nagate wondered why he was made guardian. Kobayashi clarified she didn't chose him to be a formal guardian, it was his abilities that got him promoted. Nagate pointed out the oddity of the things he's experienced so far: Kobayashi revealing her face but keeping it secret to everyone else, Hiroki not letting him leave underground, and the unusual speed of his healing. Nagate suspects Kobayashi knows there's a secret about him. The captain unmask herself and tells Nagate that they're still investigating over Hiroki and his birth; she embraced Nagate and reasoned she became his protector because she felt sorry for him. Nagate didn't get his answers but Kobayashi's reasoning was enough to placate him for now.

Back downstairs, Hoshijiro was waiting for Nagate. She wondered if he was okay since he chased after the captain. Nagate brushed off the matter, saying he wanted to greet her. It was then Izana appeared and suggested they go ride the submarine submersible right now. Yuhata barged in and felt it was a great idea. She pointed out that formal guardians can bring a guess with them and Hoshijiro suggested they all ride together in the submarine. At the entry bay door, Yuhata tried to engage Nagate's love for food by telling him about Monkfish stew, encouraging him to try it when she makes it. Weirded out by her enthusiasm, Yuhata handled the boarding procedures and secretly set the submarine for only two people. She quickly shoved Nagate into the sub in attempt to only ride it with Nagate, but Izana intervened. While fighting for the door, Hoshijiro intervened and ended up in the sub with Nagate. The door closed and the two had a private ride together.

Shizuka and Nagate becomes a couple

As the submarine shook, the two was trying to balance themselves and held each other's hand. While holding hands, both admired the incredible view of a giant squid and Nagate is amazed how the deep sea level accounts for a quarter of Sidonia. Hoshijiro noticed they already ran through the course twice and suggested they should get to the nearest exist, but Nagate grabbed her hand, telling her we're good this way. The Nagate wanted to continue having this moment with Hoshijiro but they got a gauna alert.

Norio's Sabotage & Shizuka's Death

Nagate plant his explosives around the tail of the Gauna

At the mission briefing with Ichirou, the team was informed of the mission. A collective-type gauna approximately 830 meters (~7.56 football fields) length is heading to Sidonia, with an estimated number of 27 true bodies. To prepare for battle, 36 guardians with 8 kabi spears will be deployed. Although with many true bodies, there's a main true body within GA-488 and it's their top priority to destroy it upon discovery. It's believed nearly 259 meters of GA-488 doesn't have any true bodies; they are to remove whatever placenta they can and Kunato's team is expected to sever its tail. With their objectives clear, the guardians sortied and formed a 36 clasp position to blast towards GA-488.

Within 1,000 Kilometers (~621.371 miles), the guardians broke formation and began surrounding GA-488. The gauna began attacking the pilots with its placental arms and they were forced to evade while trying to destroy the true bodies. Kunato's team managed to latch onto the rear of GA-488 and began inserting pile-driving explosives into it. The plan is to synchronously detonate explosives to sever the tail in hopes to expose the main true body. Everyone managed to set their explosives in the expected position; the final part was Norio to command everyone to detonate the charges synchronously. Unknown to everyone, Norio intentionally switched to a private channel to only directly communicate with Nagate and told him to blow the charges. To everyone's surprise, they presumed Nagate messed up and prematurely detonated the charges when it was Norio that sabotaged him.

Surprised at the detenation, Ichirou told Nagate that Norio haven't given his signal yet and that confused him. Before a proper explanation can be given, GA-488 reacted and unleashed even more tentacles upon the guardians, killing some and critically injuring others. Nagate was ensnared by a tentacle and critically injured. Hoshijiro intervened and tried to save Nagate, but Shizuka's unit lost its lower body and stuck on top of the gauna. The tentacles destroyed her unit, killing her, and subsequently devoured her body. Nagate's unit had to be dragged back to Sidonia for medical attention.

Back at Sidonia, Nagate woke up to find the Honoka sisters waiting worried for En (critical condition). As soon as they saw Nagate, they blamed him. Izana found Nagate and surprised he was able to walk so soon. She brought Nagate back to his room and insisted he should rest. Izana remarked his injuries were severe and it wouldn't be strange for him to have died from it. Confused to what happened, Nagate asked Izana about the gauna and how he ended up here. Izana tried to calm Nagate down and she'll get the doctor; Nagate sensed something was off, but Izana insisted he should rest.

Nagate turned on the TV and he learned their counteroffensive was considered a success as they drove GA-488 away. Only one of the 29 true bodies escaped and the reporter praised Norio for taking down four true bodies. Norio remarked he wasn't satisfied with the battle and the reporter pointed out Nagate's blunder. Had the tail been successfully severed, it was believed they would've had a decisive victory. Norio pretended to graciously take responsibility, saying he failed to lead his team properly. As Norio commented about losing a friend, Nagate can see the news reel confirming Hoshijiro's death. Izana realized Nagate saw it and tried to flip it to the weather channel but it was too late.

It's now winter in Sidonia. After Nagate recovered, he reviewed the battle records. Seven guardians died on that operation and Nagate found himself distraught and upset over Hoshijiro's death. Haunted by Shizuka's death, Nagate shut himself in and didn't eat. Lala eventually got Nagate out the door and Izana spent time with him, praising his valiant efforts. As they walked through the snowy streets, they encountered a protestor, saying the Immortal Ship Committee is the cause of the Gauna Conflict and the reason why so many have died. The protestor goes on to say the committee intends to destroy Lem VII and that there's proof primeval life exists on the planet. A skeptic criticized the protestor, believing the protestor is a quack for saying Sidonia never left the solar system earlier. As Izana and Nagate left, three people noticed Nagate and trailed him.

Izana tried to cheer Nagate up by making a snowman together, but he continues to brood; she decided to get some warm drinks for the both of them. Unknown to Nagate, Norio's sabotage created large public resentment against Nagate and there's been mounting requests for his suspension. Alone behind the trees, three men blindfolded and tied Nagate up; they beat him and broke his front teeth, telling him to stop piloting. By the time Izana came back, Nagate came out of the trees with a bloodied face and his assaulters gone. Izana helped untie him and wanted to get him medical attention, but there was no time as he got a sortie call. After patching himself up, Nagate was heading to Tsugumori when Norio stopped him. Norio warned Nagate to not blame him for Hoshijiro's death. Confused by his comment, Norio didn't elaborate and went to his gardes.

Ghost of Hoshijiro & Sidonia's Hero

Sidonia had fired a planetary missile earlier at a gas planet. Kobayashi believes GA-488 is hiding inside there and other potential gauna as well. With the planet destroyed, sensors picked up several gauna readings that resembles gardes units and called for a sortie. In a 12-man sortie in three teams, Team Samari will face GN-489, Team Imada with GA-490, and Team Kunato with GA-491. Ichirou warns the guardians that the gauna can replicate the Higgs Particle Cannon and the first in history for them to imitate Guardian-shaped placenta; he calls for their caution in combat. Once nearing their targets, the guardians were surprised that all three targets have taken the form of Hoshijiro's 702 Gardes unit with GA-901 dangling a placenta pilot, imitating Hoshijiro. Although disturbed by the site, the guardians begin their attack.

Team Samari performed a serial clasp formation before breaking off and began firing above GA-489. As they attacked GA-489, they were surprised it was imitating Hoshijiro's voice over their com frequency and eerily mention how much it hurts. Kobayashi reminds the teams they are dealing with gauna and to focus on attacking; Team Samari exposed GA-489's true body and destroyed it.

On Team Kunato's end, Nagate got emotional over the situation and flew ahead of his team to GA-901. The gauna had a placental pilot dangling as its right arm and Nagate tried to reach out to it in hopes that Hoshijiro somehow survived. However, Hou warned Nagate that is a gauna and it won't understand them. En decides to fire her particle cannon only for GA-901 to return fire and blew off her unit's right arm. Nagate decided to make a precision shot; he severed the placental pilot from its main body and fired a particle beam to its head. Taking advantage of the push, Nagate signaled Norio to finish GA-901 and he destroyed it. Focused on the severed placenta, Nagate tells Ichirou he's going to recover the placenta sample. Ichirou at first was against it as there's still another gauna target but Kobayashi approved it for scientific study.

Nagate retrieve human form like placenta of G451

While Nagate goes to retrieve the sample, the remaining guardians converge on GA-490. This gauna knew how to evade Imada. It returned fire and killed Imada with a rod-shaped object through his head. GA-490 remarks over the coms how she killed one target and continues to laugh as the guardians try to defeat her. Nagate got his sample; he and the rest of the team regrouped to engage GA-490. By the time they go there, Team Imada was wiped out. Ichirou tells the surviving teams to engage GA-490 as if it were inter-guardian combat instead of anti-gauna tactics to adapt.

Team Kunato engages GA-490; En and Hou fires their particle cannons for a cross shot. Unfortunately, GA-490's evasive speed was greater than actual guardian units and destroyed Hou's cockpit. GA-490 caught En's unit and ready to kill when Nagate intervened. Nagate blocked the attack and tried to appeal GA-490 as Hoshijiro. GA-490 seemed to react in rage and called forth additional gauna. The gas cloud behind them was actually gauna laying dormant and reformed itself into a Mass Union Ship. Ichirou called for a retreat while Kobayashi decided to fire Sidonia's main cannon. Nagate and the surviving guardians formed the clasp formation and jetted back to Sidonia as it fired upon the gauna and the Mass Union Ship retreated.

Back in Sidonia, Izana was reviewing the report on the recent battle. Izana noticed the report mentioning Nagate securing a placenta sample. Curious about that sample, Nagate explains it's a placenta replica of Hoshijiro. GA-490, the only one that survived their encounter. Later, on the surface of Sidonia, Ichirou reviews the specimen Nagate brought in and it calls his name. To further understand the sample better, ET Researcher Numi Tahiro called Nagate to see how the sample would react.

On a Saturday morning at the Outer Space Lifeform Research Center, Nagate and Izana went to visit Numi. They rang several times and nobody answered. Numi overslept and ran late for the lab; the duo arrived before she did. Numi apologized for her lateness and expressed gratitude for bringing such a specimen imitating so close to human beings. Weirded out by the long handshake, Nagate accepted the compliment. Izana was there to substitute Ichirou as he had something to do and she's standing in for him.

To test the GA-490 sample's intelligence, Numi had Nagate suit up in a special safety suit and made sure he was aware of safety procedures with placenta. Nagate was disturbed to learn from Numi that the sample spoke is name. At the containment room, the shielded door was opened for the placental Hoshijiro to see Nagate. As soon as Nagate called out to it, the sample reacted and launched its tentacles towards Nagate. Fearful it might harm Nagate, Numi resealed the door and the three later went to a restaurant to eat.

Sitting at the counter, Numi was surprised as its the first time a placenta reacted that way to a human. Nagate was in deep thought about it when Samari Ittan, Kouichi Tsuruuchi, and Tonami arrived to greet him. Jumping in on the topic of the sample, Samari asked about the placental Hoshijiro and Numi remarked it's a close replication of a human being. Samari mentioned how it fought like a guardian pilot and forced them to think up of new strategies. Tonami felt it would be an easier fight since it's a "human opponent"; he hasn't been able to find a formidable opponent in particle cannon usage since Izumo's death. Samari thought Tonami relies too much on his cannon because even though it can strip placenta, the gauna also feeds on it as energy. Tsuruuchi remarks Tonami is an impatient person because if he assist in three victory battles against the gauna, Tonami gets to photosynthesize one-on-one with Samari; she rejects the idea of photosynthesizing with any of them. Numi noticed someone is missing and Tonami mentions his brother has shuttered himself at home and sulking due to learning he's assigned to retrieving a kabi spear for tomorrow. After eating and several hours later, Nagate was called to sortie.

At the hanger, Samari yelled at him for being late. Confused that he's supposed to arrive at 7, Samari told him a new development has happened and he sortied with Team Samari to substitute Tonomi's brother. After launching out, Ichirou disclosed the mission. There has been an unobservable field moving at high speed from the mass union ship towards the location where they're supposed to retrieve the kabi spear; it's likely the gauna and their mission is to retrieve the kabi before the gauna reaches it. In a standard clasp position, the four thrusted towards the unidentified object. Kobayashi commanded Sidonia to fire two rounds of the heavy mass cannon ahead of the team to uncover what they're about to deal with and it revealed a cloaked (placental camouflage) gauna.

Breaking the clasp formation, Tonami fired his particle cannon and the gauna reflected the attack back, killing Tonami. Nagate couldn't help reflect another person died, but there was no time to mourn as the gauna attacked. Samari retrieved the kabi spear but attacking it is still a challenge. Tsuruuchi points out those reflective orbs prevents them from using their particle cannons and Samari thinks there's too much placenta to strip off with conventional weapons with a big recoil. Without explaining himself, Nagate charged Tsugumori into the gauna, encouraging it to attack him. The gauna chomped on Tsugumori, giving Nagate the chance to fire his right forearm gun from the inside without concerns of recoil and exposed the true body. Samari swooped in for the kill and slayed the gauna. Samari credited Nagate for his bold tactic and he accepted the gratitude. Unknown to Nagate, Norio has been investigating into Nagate and discovered the unusual conditions for his guardianship: Nagate can only be a guardian if he participates in all battles (a practical death sentence).

Back at Sidonia, Izana and Nagate are walking together, talking about school. It's the middle of vacation, but Nagate talked about getting his primary education due to his underground life; Izana didn't think he needed to. Izana mentioned her grandma (Yure Shinatose) wants to meet him and welcome him to stay for the night. Making to Izana's home, Yure wasn't present; she left a note saying she had something to attend to and will come back tomorrow. With Nagate starving, the two decided to go fishing.

At the river fishing (despite a sign against fishing), Izana noticed Nagate brooding and told him not to blame himself and it's not his fault. Nagate reflected how the placenta he brought back had such an uncanny resemblance to Hoshijiro. He was thinking if the gauna can perfectly reproduce Hoshijiro, she would be human; Izana made it clear that placenta is placenta before he could finish. Unfortunately for Nagate, Izana accidentally hooked Nagate's his lip and the two fell into the water. Getting out of the water, Izana apologized and helped Nagate remove the hook but he's got blood on his lower jaw. Just then, Yuhata appeared before them. She has been staying at a nearby inn and welcomes them to join her in an intersex hot spring.

Yuhata wanted to spend some alone time with Nagate, but Yuhata wondered why Izana joined them. Wanting to get closer to Nagate, Yuhata went up to Nagate and asked about his mouth injury. To their surprise, Yuhata noticed the swelling is almost gone and Izana noticed he regrew his teeth. Because Kobayashi warned him to keep his healing factor a secret, he tried to pretend it still hurts. Just then, Nagate jumps out of the bath (completely naked in front of ladies) when he realized he got a sortie call.

Sidonia sortied four teams (16 guardians) to face the gauna. Once they reached within range, the teams broke formation and Team Migita took lead on the attack. To everyone's surprise, the GA-493 began morphing into a streamlined missile, heading towards Sidonia. Samari called Tsuruuchi, Tonami, Migita, Nagate, and Nakabayashi to immediately form a six guardian clasp formation to catch up with GA-493 at maximum output. As they tried to close the distance, Ichirou warned the guardians not to use their particle cannons as blowing up GA-493 would get them caught in the explosion as well. Nagate had an idea but didn't have time to explain; he broke formation and deployed his grappling line to GA-493 to close the distance.

As he reached close to GA-493, the tearing force ripped Tsugumori's left arm out; Nagate managed to latch himself onto the gauna. He managed to dig into GA-493 and pulled out an explosive placenta out of it. GA-493 began changing it's trajectory and form to fire an explosive round at Sidonia. Kobayashi had Sidonia fire its particle cannons to take out the incoming projectile. Now wrestling GA-493, Nagate managed to expose its true body and signaled Samari to finish GA-493 off. While Sidonia was happy to know GA-493 was defeated, Nagate's teammates had a different reaction. There has been a consistent rumor that whoever assist in the most victories will get to photosynthesize (seeing her naked) with Samari; his fellow male guardians think Nagate wants to see her naked. Samari was angry and wondered who has been spreading such rumors, she didn't know it was Ichirou that did it to motivate the men to fight harder. After Ichirou called everyone back, Nagate rejoined Izana.

Returning to Izana's home, the two were surprised to see Yuhata inside and wanted an explanation. Yuhata claimed she has been watching the house and cooking for them. After finishing dinner, Nagate couldn't help but savor the fish Yuhata made. Izana wondered why haven't Yuhata returned to the dorms; Yuhata felt she couldn't leave the two alone (suggesting a romantic stay over with the two). Flustered by Yuhata's words, Izana was worried Nagate would realize her attraction to him, but he was too busy thinking about delicious fish they just had. The three would end up sleeping in their own beds with Yuhata in the middle.

Some time later, Izana and Nagate was walking pass Lala Hiyama at the dorm and found her thoughtful while cleaning. Izana encouraged Nagate to call out Hiyama's first name to get her attention. When Nagate called her Lala, Nagate's reflection on the glass convinced her it was Hiroki. Instead, Nagate ended up apologizing when he mentioned Izana suggested it; Lala grabbed Izana and hung her right outside the window to scare her. Later while feeding Nagate dinner, Lala gave Nagate a generous bowl of rice; Izana thought she's giving Nagate special treatment (because of her affection for Hiroki). Lala feigned ignorance and reminded herself not to be too obvious.

At the OSL Research, Nagate spends time with the placenta Hoshijiro. He thought back about Hoshijiro's words about the gauna trying to befriend humanity but don't know how to connect with them due to their differences. While observing the placenta with Numi, Nagate wondered is there's a difference between a replicated placenta and the original person if the gauna fully replicates the person's personality and memories. Numi answered it would be considered the same as the original human being but as someone from Sidonia, she can never acknowledge that fact. Heading back down, Nagate sees Izana and she tells him she's a guardian now. Nagate was happy and congratulated Izana, but she wasn't happy as guardians have a low survival rate. Izana felt Nagate was seeing the placenta because he's still hung over about Hoshijiro; he tried to explain he was asked by OSL Research, but she wouldn't hear it and walked off. Nagate tried to pursue Izana, but she wanted him to stay away until she slipped and fallen off from a giant pipe. Nagate manage to grab Izana and told her their time isn't over yet.

A chain-type gauna appeared on sensors and Nagate was called to sortie. At the hanger, Nagate was surprised to find out Tsugumori has been equipped with a kabi spear. Ichirou explained that was done because he's a spearman; there has been a change in the roster and Nagate will lead his own team with Ichirou as his teammate. Nagate was surprised to learn he just got promoted and now sorties to combat the new threat. At the CIC, Ichirou had Yuhata promoted as the new XO and briefed everyone on the mission. Small Mass Union Ship 21, dubbed as the Ocarina, has launched smaller gauna towards Sidonia. Shaped in a ring, sensors detected 48 true bodies and as the guardians reached to proximity, they realized the ring is actually 48 gauna imitating the guardians in clasp formation and Benisuzume (GA-490) is part of the pack.

The guardians broke formation and picked their targets. With a combination of Yuhata's instruction, Ichirou's tactics, and Nagate's piloting skills, they were winning. Nagate single-handedly took out 19 enemies, but credited Ichirou being a great pilot. With 13 gauna remaining, Yuhata commanded Nagate's team to support team beta. As Nagate closed in, Benisuzume took out unit 211. Benisuzume tried to use her placenta to infect her way into the cockpit to kill the pilot, but was distracted when Nagate told her to stop. Tsuruuchi tried to help Nagate firing at Benisuzume, but the gauna used their comrade as a shield instead. As they regrouped, unit 087 was thought to be destroyed but it suddenly fired its particle cannon onto Sidonia; the gauna infected and took over the unit.

A Sidonia, it was Izana's first sortie and she's been assigned to guard Sidonia. Benisuzume appeared and charged at Izana. With a weapons malfunction, Benisuzume battered Izana's unit. The rest of the guardians elminated the gauna and only Benisuzume remains. Kobayashi commanded Nagate to join Norio's team in clasp formation and also pointed concern over his behavior with Benisuzume. As the guardians flew to their appointed area, they discovered their enemy signature is a decoy. Benisuzume destroyed Izana's unit when Nagate intervened. He stopped GA-490 by attacking its center of gravity. Both Nagate and GA-490 fired their particle cannons and when the dust settled, the gauna fled and Kobayashi declared their battle over. Back at the hanger, Nagate was surprised to see Izana alive; she lost her right arm and left leg. However, he was glad to see her alive.

Nagate was summoned Kobayashi; she wasn't happy for his tardiness and expected him to be punctual. Kobayashi then told him about a legendary hero pilot without identifying Hiroki. She told him that their hero saved them from many dangers and they're facing great danger again. She showed Nagate that the Ocarina and the Huge Mass Union Ship is 3 light years away from the alert zone. She tells him that 100,000 pacifists want to colonize the Lem System and immigration has already set in motion. They believe that evading the gauna is the best way to avoid conflict, but Kobayashi believes clearing out all the gauna from the Lem System is the best solution; she wants Nagate to be that hero. Nagate answered Kobayashi's call and committed himself to the cause.

Nagate, Yuhata, and Lala would later go visit Izana. By her grandma's suggestion, she opted for cybernetic prosthetics as organic ones would take too long. Izana took the chance to thank Nagate for saving her life. Moving to the canteen, Lala wondered about Nagate's well-being. She was concerned about him being overworked and keeping things to himself like Hiroki; Yuhata feels Nagate he's a strong person and not a complainer.

Exploring Sidonia Mystery & Chimera Secrets

After Izana recovered, Nagate met up with Yuhata and Izana for a outing together. Because Yuhata want to be alone with Nagate, Izana's presence is an annoyance and both blame him for double-booking the outing with them. Exploring a hidden tourist site, the trio found the Gravity Inn and Nagate was surprised to find the captain disguised as the manager of the inn. Nagate didn't expose her identity and while walking in, Ochiahi (clone) was also present to explain blending in with the ordinary crew is her own pleasure. While getting comfortable with their room, Yuhata shared a book: Tales of Sidonia's Mysteries. It was there the book explains how the original Ochiai was executed at the year 904 (Sidonia Era) for his misdeeds; Nagate couldn't help but wonder about the Ochiai he knows. They continue to learn that Ochiai perform dangerous experimentation with the gauna that led to a ban against studying the placenta on Sidonia. The most terrifying and savage of experiments was a chimera made up of monster and human. Yuhata mentions that Ochiai's lab still exists and locked away within Sidona; she believes the facility is hidden at an entrance near the base of the lake. Yuhata has acquired a terminal key to reveal the lab once again.

The trio later headed to the base and Yuhata used the key to open the doorway. The door closed after they entered and they're unable to reopen the door. Stuck in a dark spooky place, they couldn't call for help they venture deeper into the tunnels for a potential exit. As they walked through, the trio heard something and found a bunch of giant locusts hanging on the pipes. Freaked out about the bugs, the Izana and Yuhata held onto Nagate for security. As the bugs started hopping about, one landed on Izana and scared her while holding onto Nagate. Because of her cybernetic arm, she squeezed Nagate's right arm hard enough to squirt blood. While sitting down to rest, Izana apologized for injuring Nagate. Just then, a sewer eel passed by and freaked Izana again, prompting her to grab Nagate's left arm and injuring him the same way earlier.

The three continued their journey through the dark stairs. As they walked, Nagate realized it was a white eel that scared Izana. Yuhata wondered did Nagate ever eat them and he confirmed they were delicious. Just then, Izana freaked out over seeing a masked figure in the shadows. Izana hasn't been holding up well in the tunnels and wants to go back. Nagate's nose smelled a working switch board and told the ladies they might have a way out. After getting the elevator working, the trio boarded to lift in hopes of an exit. Surprised at his technical ability, Nagate explained he used to repair junk in his earlier days. As the elevator traveled, the computer warned them they're heading to a zero-gravity area. Izana didn't have any gravity boots and Nagate offered to hold her so long as she didn't squeeze too hard. Exiting off the lift, they encounter a doorway marked MSCF (Max-Security Containment Facility) 5. Yuhata realized they're at a place that requires high clearance. Just then, Yure Shinatose (masked) appeared and warned the trio they are trespassing. Before they could explain themselves, security forces arrived with tranquilizers and knocked out everyone. Nagate was resistant towards the sedative and needed to two more rounds before getting knocked.

After Nagate woke up, Yure finally made fomral introductions to Nagate and expected him to keep her status a secret. Yure then escorted Nagate to a hidden room, revealing a preserved female-like gauna. Shocked what he was seeing, he asked Yure the nature of this specimen and Yure explained it's a chimera made of placenta and human cells without a cell. It's an earlier experiment of Ochiai and Kobayashi arrived to elaborate they're using it to produce artificial kabi out of it. She explains the chimera emits a certain radiation wave that attracts the gauna, but they have the power to exterminate the gauna. Kobayashi declares that Toha Heavy Industries has been restored and making a new artificial kabi weapon; she wants Nagate to pilot the prototype. Back at the Gravity Inn, Izana and Yuhata woke up to find themselves in their room and unclear how they got back. Nagate tried to excuse they were too tired to remember and told them dinner will be ready soon.

Toha's Revival & Prototype Trials

With Toha Heavy Industries' return, Yuhata and Nagate were sent to see the engineers. Walking through the heavily piped corridors, Yuhata felt the place looks different than their expectations and Nagate agreed. The two bumped into Tanba and told him they're here to get information about the new weapons and looking for Sasaki. Just as they asked, Sasaki appears before them and surprised to see the chief engineer is also the guardian mechanic; she assures she'll continue servicing the guardians in between. As they walk into their R&D area, they see a next generation prototype propulsion pack. Nagate was surprised to see them also developing the Ultra-High-Speed Bullet Accelerator and Sasaki was surprised that Nagate would even know about it since there are no released reports. Nagate explained that weapon was part of his simulator while living underground. To his surprise, Nagate found the exact simulator at the corner of his eye. Sasaki didn't believe him, seeing his comments as nonsense. However, a subordinate mentioned the simulator is an improved version of the model when the project started; it's likely Nagate is being truthful. Surprised Nagate didn't lie, she asked when did Nagate started training and he told her since he was little. He bragged he defeated Hiroki's top score by six. Even without breaks and controls, he can still stand in a fire fight until he's out of ammo.

After the visit at Toha, Nagate had dinner with Izana and Lala at the cafeteria while watching the TV. The news is reporting the Pacifists Advancement Party's ship took off from Sidonia right now. 100 out of the 100,000 applicants were selected to prepare the Lem System for a migration wave. Nagate wondered how will they defend themselves without weapons in case the gauna attack; Lala explained they're under the presumption they won't be harmed so long as they don't attack. The purpose of Sidonia was to ensure mankind's survival through propagation; it was decided that if there was a habitable system, they would colonize it with 50,000 settlers. With the massion union ship nearby though, Lala believes it's a waste of resources and personnel. After dinner and going to bed, Nagate wondered how great the world would be if the gauna didn't exist for people to live on a planet.

Nagate would later sortie to trial test the new Ultra-High-Speed Bullet Accelerator for Toha end yielded good results. Sasaki was pleased with the results and complemented on Nagate's skills for his age. Barely a few minutes in the hanger, a gauna alert sounded off. A gauna had launched from the Ocarina and heading towards the advance party ship; there was no way a sortie would be fast enough save the ship from the gauna. Nagate asked Sasaki permission to use the new prototype back unit now, but she was hesitant. Nagate tried to get Kobayashi's approval, but Sasaki had concerns. The anti-recoil device isn't adjusted and not synchronized with the back unit yet; it would be difficult to accurately hit a high speed target even within firing range. Kobayashi approved the sortie, believing this will be a good chance to prove the foolishness of the pacifists.

As Nagate prepared to launch, Kobayashi declassified the information on the new weapons and the engineers fitted Tsugumori with the prototype backpack. With incredible acceleration, Tsugumori blasted out of visual range instantly and closed the distance with the gauna. Despite his speed, Nagate was still not within firing range; he decided to fire anyway to prvent the gauna from attacking the settlers. Firing his artificial kabi round, he missed the true body and Tsugumori spins out of control because of the recoil. Already adapted to such situations during his simulation days, Nagate quickly readjusted and regained stability. Now within firing range, Nagate fired and nailed the true body this time, saving the colonists. In the aftermath, the colonists blamed Sidonia's weapons testing as the reason the gauna attacked and didn't change minds for people who want to colonize the Lem System.

Norio's Retirement & The Return of Ochiai

Nagate would later go visit Norio to talk. While waiting for him to answer the door, he was amazed for it's massive estate. Norio appeared and Nagate asked is he retiring from piloting; Norio's silence was his answer. Nagate would tell Norio about his early days living in the tunnels with Hiroki, but felt lonely after his grandfather died. He explains it's probably the reason why he love the food, animals, and people of Sidonia. Nagate makes it clear he still can't forgiven him (suggesting he knows what Norio did), but Norio is one of Sidonia's people he love. Nagate compliments Norio for his piloting skills and hopes they can battle to protect Sidonia again one day. Nagate tried to invite him for dinner with the pilots tonight, but Norio heads back inside getting emotional. Unclear is he willing to join, he leaves a memo behind with the information if he changes his mind.

At the Onion Whale Restaurant, Nagate tried to find his party but forgot the name of reservation he used. The server knew which party he was referring to and sent him to dine with the guardians. Nagate didn't realized he joined the wrong party and the pilots simply welcomed him to the dinner; he was supposed to dine with Izana and Yuhata. Because he didn't bring his phone, the two was worried and Yuhata decided to use his tracker and realized his coordinates is overlapping their location. It was then the two heard the guardians getting too loud and heard them calling Nagate's name. The two found Nagate eating so well and Izana called out Nagate in anger, slamming on the wooden beam. The beam was supporting the suspended hot pot and all the hot soup suddenly poured on Nagate's side. The guardians needed water quick and the hook slammed into the fish tank, soaking everyone in the room. Nagate was flushed outside of the restaurant, on the edge of the roof.

Later at the research lab, Nagate spend time observing the Hoshijiro placenta. Just as he bid farewell to it, the placenta stood on the ground. Nagate quickly called Numi to notice this surprise behavior. The placenta is pointing on the glass where Nagate's finger is and imitates him. Numi had to remind Nagate that even though the placenta could retain Hoshijiro's memories and starts acting like a human, it's still a gauna under quarantine. After Nagate left, Norio and Mozuku came to visit. Unknown to Numi and everyone, Ochiai has taken over Norio's body.

Norio began investigating deeper into Nagate with limited success, but his search eventually led him to Ochiai. Norio wanted to investigate the mystery of Ochiai and discovered the Kunato family provided Ochiai a lab facility but sealed had it sealed after his demise. His lab still sealed for a century, Norio reopened Ochiai's lab for discovery. Barely there for a few minutes, his body was taken over by a Sidonia Blood Nematode and his personality was taken over by a copy of Ochiai's personality. Using the body of Norio, he was able to take advantage of Norio's executive powers and access privileges over Kunato Developments and Sidonia. Ochiai put Numi under his control with his nematode and now has access to the Hoshijiro placenta.

Asteroid Battle & Benisuzume's Return

At the hanger, the guardians have been summoned to sortie. 107 gaunas has been detected coming from the Ocarina and the engineers are preparing final installations before allowing the pilots to launch. As Nagate and Izana head to their gardes units, they can see everyone scared and comforting each other. Izana sees Nagate off and they all launched for the battle in silence. Despite the anxieties of death, Nagate's ace skills and the new kabi rifle increased the guardians' combat strength. Ultimately, the guardians defeated all 107 gauna without a fatality.

After the battle, Yuhata and Izana have a meal with Nagate. As he was enjoying his noodles, the two were impressed how they wiped out the gauna without a fatality and credit Nagate's piloting skills. Izana felt optimistic that the pilot survival rate increased and feels like there's hope for them. However, Yuhata pointed out this battle was less difficult because Benisuzume wasn't present in the battle; they can't let down their guard yet. As Nagate eats, OSL Research called him to come and he heads off; Izana reminds Nagate of his promise to teach her how to shoot later. At the OSL, Nagate found the Hoshijiro placenta changing her pilot suit into a dress for him to see. Nagate was pleased by her look and the placenta starts writing out his name, but breaks the marker. Numi (under nematode control) jested he should go inside, but admits she was kidding as the tentacles is strong enough to puncture armor. Nagate felt good from the experience and left in glee. He realizes he's still not sure what to do, but he'll focus on piloting Tsugumori for now.

Later at the hanger, the guardians are preparing for training practice. Nagate finished suiting up, but he couldn't get use to the catheter snaking through his groin. Nagate wondered is Izana doing okay, but she reminds him not to drag his feet or Yuhata will be mad again. Just then, Nagate got curious about how Izana's catheter works; Izana knocked Nagate to the ground for that insensitive question. Inside the cockpit, Yuhata noticed Nagate injured (a bloodied nose and a black eye) but brushed it off as him falling over; she reminded Nagate it's important to maintain his life and apply caution before launching.

While Nagate and the other guardians were busying practicing with their new kabi rifles, Ochiai had proposed to Yure Shinatose about using the Hoshijiro placenta as a medium to revive the chimera project. Ochiai intends to impregnate the placenta to create a gauna to help mass produce the kabi bullets they're running short on. After Nagate came back from training, Numi informed Nagate that the placenta sample has been taken. Bothered that the Hoshijiro placenta is gone, he wanted to know where it went but Numi refused to answer and hung up on him.

Later, Sidonia detected an asteroid heading their way and the rear is filled with gauna; Nagate and the guardians were summoned to defend their home. As Nagate and the other guardians head to their gardes, Yuhata explains the operation is to eliminate the incoming asteroid and the gauna accompanying it. There's a possibility of a near-surface battle inside the asteroid's gravitational pull and warns caution to the pilots. As they head closer to their units, Tsuruuchi just had to joke about Samari's breasts under gravity conditions and got smacked for it. Ichirou noticed Nagate seems distracted, but he couldn't explain about his feelings after learning the Hoshijiro placenta is gone.

Sorting in a 96 clasp formation, the 1st and 2nd platoon are composed of 48 units. As they fly closer to the target, Yuhata updates them from the bridge: there are 312 confirmed gaunas on that asteroid, 50 are concentrated in the large crater on the back of the asteroid, considered linked-type gauna, and they're providing thrust to the asteroid. Yuhata explains there are 6 hours until the asteroid reaches the line where Sidonia can't adjust course to prevent a collision. They have until that time to hit the asteroid with an anti-planet missile; their top priority is to take out their source of propulsion and prevent the asteroid from evading the incoming missile. Samari commanded the guardians to stop acceleration, turn around to adjust course, and decelerate. As the guardians reach loser to the asteroid, Yuhata noticed Nagate was breathing heavier than usual, but he insisted he's fine. Samari then commanded everyone to break formation and attack the gauna.

As the guardians begin sniping off the gauna; the gauna reacted and returned to the asteroid. With the asteroid getting closer, the guardians retracted their rifles and 1st platoon is taking a Route A circular orbit while 2nd platoon is taking Route B in a polar orbit. The 1st platoon guardians had trouble adjusting as the gravity of the asteroid began pulling them; Unit 561 was destroyed due to succumbing to the gravity. Things got more difficult as gauna began firing their own particle beams on the surface of the asteroid. Casualties began mounting as the pilots have trouble handling with the gauna while dealing with their guns' recoil and gravity, making evading hostile fire impossible. Meanwhile, the 2nd platoon made it to the crater side and attempted to blow up the main body within its core. Unfortunately, their fire power wasn't enough to penetrate through into the main body. Just then, sensors picked up a singular gauna coming out of the asteroid: it's Benisuzume.

With less than three hours before the asteroid reaches the borderline, Benisuzume wiped out all of the 2nd platoon and only 32 units remain with the 1st platoon. Yuhata was taken back by the sudden destruction of the 2nd platoon and haven't gotten a better plan; she reminded the surviving guardians how much time is left and encouraged them to quickly take out the asteroid's propulsion out. Tsuruuchi, Ichirou, and Samari agreed that their circular orbiting method isn't working and they have to fly in closer to take out the gauna. The 1st platoon showed some success in mowing down the gauna, but the enemy adjusted their particle beam angles and fired at the low altittude guardians charging through. From the bridge, Yuhata had the remaining guardians to fly through three canyon routes that leads to the power source of the asteroid's propulsion and Nagate chose the third route (C) to get there. As they flew closer to their target, gauna have been detected approaching them at high speeds and started losing additional guardians. Nagate took out one of the high speed chasers, but lost the other one. Right behind him, a large moth-like gauna appeared and fired a powerful particle beam at Tsugumori. Fortunately, Tsugumori has an anti-beam coating and reduced some of the damage, but the gauna has now latched onto the unit and Nagate wrestles for control. The gauna fired its beam point blank at Tsugumori, damaging its head and chest; Nagate managed to get his gun and finished off the gauna. Although he managed to win, Nagate lost consciousness and began falling. Izana managed to grab Tsugumori, but they were too heavy; both units went down and roughly crash landed on the asteroid surface. With Nagate and Izana unable to respond, Kobayashi commanded the firing of the planet buster.

As Sidonia prepare to fire the planet buster, surviving guardians saw Tsugumori and Izana's unit; they dragged them into a secured trench where the rest of the guardians have held a defensive line. Guardian 738 began to triage Nagate, but Kobayashi made it clear that Nagate is to be treated within Tsugumori and not to be removed from the cockpit. Nagate regained consciousness and reported back in with the bridge that his helmet is broke, but he's able to function without it. With only 1 hour left on the clock, Nagate realized his squadron won't make it in time; he told his surviving squad to retreat back to Sidonia. Ren had to ask what does he plan to do and he explained his back unit contains a new prototype Higgs Engine; she felt it was unfair how Nagate always gets special equipment. Nagate declared he's going alone from here on out and told his squads he's counting on them to help their friends. Before parting ways, Ren gave Nagate a single artificial kabi round to help get revenge for Hou in her place; he accepted the bullet and took off.

The remains of Ichirou's and Samari's squad are heading to their target when Higgs Particles suddenly saturated the canyon and blew up several of their units. Benisuzume has appeared and stared discharging waves of particle bolts towards the guardians. Nagate appeared and took on Benisuzume, telling Ichirou and Samari to go take out the propulsion source without him. Despite their concerns, Nagate assures them Tsugumori can handle Benisuzume due to it having anti-particle coating on its plating.

With only 20 mins left, Nagate faces Benisuzume alone as the surviving guardians make it to the trust source. Everyone was surprised to find out the asteroid's propulsion activated and charging towards Sidonia; they now have 13 mins left. With Benisuzume attacking and without his gun, Nagate adapted Ren's bullet to Tsugumori's right hand. He charged the unit's right hand and fired a rocket punch at Benisuzume and seemingly destroyed it. The surviving guardians made it to the thruster source and took out its power source. The guardians quickly got out of there as there was only 30 seconds left before the planet buster missile impacts. To everyone's joy and relief, the asteroid was vaporized. When it was time to report, Sidonia discovered 10 (out of 96) guardian pilots have survived, including Ichirou, Samari, Nagate, Izana, and Tsuruuchi. Unknown to everyone, Benisuzume's true body survived and regenerated itself in space.

Back at Sidonia, the surviving pilots and familiars to the 86 KIA guardians held a funeral. During this time, Nagate was at the hanger and Sasaki was angry to see Tsugumori so damaged. As Sasaki chokes Nagate with her wrench, Nagate thought it could be repaired, but Sasaki remarked the damage is so great it would be better to build a new unit. Nagate was saved when Kobayashi and Ochiai (clone) appeared to inform Sasaki to begin mass production of the Type 19 Guardians.

Nagate would run late meeting up with Izana. She was expecting him to express his gratitude to him, but he was focused on food. However, their moment was ruined when his watch alerted him that En Honoka has awakened from her coma and rushed to see her. Nagate couldn't think of anything to greet En with and decided to get her some onigiri. He figured if she doesn't want it, he could have it all to himself. Unfortunately, he opened the door to find Ren and En getting naked for photosynthesis. En was still upset with Nagate's screw up (when Norio sabotaged him) and when he caught her naked, it only add fuel to the fire. Nagate tried to quietly exit himself out, but En's raging kick blew out the door. The force of her kick had the door slam on Nagate, break his nose, and knocked him down, crushed by the door. Nagate survived the encounter and got his nose patched up.

The following day, Nagate was eating with Izana when Ren appeared before them to apologize. She wanted En to apologize to Nagate, but she couldn't do it and jumped away. Ren apologized, explaining they're technically five years and still immature despite the special compressed mental training. Nagate insisted the fault is his and glad En is well. Ren admitted her own misunderstanding of him and apologized; Nagate took the chance to thank her for giving him the body piercing bullet as it was useful during combat. Ren blushed and thanked Nagate for keeping his promising, crediting his robot punch and the two laughed over it with Izana flustered.

Later at the escalators, Nagate found Numi and wanted to talk to her about the Hoshijiro placenta. However, Ochiai (posing as Norio) admitted Kunato Developments took over the placenta. Worried she might have disected, Nagate wondered if she was chopped up. Ochiai reminded Nagate that he's allowing his personal feelings with Hoshijiro cloud his judgement as the sample is just placenta. He credited Nagate for his great job in handling Benisuzume and will root for him. Nagate would back to his dorm to sleep.

En visited Nagate with onigiri to apologize. Before she could knock on his door, Samari came to see him. En hidden herself by hiding on the ceiling while Samari wakes up Nagate to go eat out with her. At a izakaya (japanese bar), Nagate ate all sorts of snacks and the two talked about piloting. While Nagate praised Samari's skills, she negatively commented she couldn't give proper instructions to people and so many died. Samari was admitting her own anxieties and stopped herself, but Nagate offered to lend his ear to her any time. Touched by his kindness, Samari commented she wanted to go for photosynthesis (suggesting she wants to get naked with Nagate). Unfortunately, Nagate fell asleep after eating and Samari ended up drinking more sake.

In between, Ochiai (in Norio's body) helped transfer out all the data that was locked away in Ochiai's auxiliary brain. With Sidonia's lost database and Ochiai's research data, Sidonia can comb through Ochiai's studies to understand the gauna better. However, Kobayashi understood the dangerous nature of Ochiai's work and declared it all classified. Only the commander will have direct access to the database; she doesn't know Ochiai is already out and manipulating events to his advantage. Ochiai revealed to Sasaki that the Hoshijiro placenta has been impregnated with a human male sperm and the chimera inside is about to be born after two days of gestation.

On a special outing with Izana, Yuhata called for Nagate to immediately come see her about the Hoshijiro placenta. Izana was disappointed as she already made lunch, she had hoped Nagate can handle the situatio by phone, but Nagate remarked Yuhata wants this meeting to be conducted in person. Angry about the situation, Izana stormed away and he went to see Yuhata. At the meeting, Yuhata was there to convey words from Kobayashi: he's to not worry about the placenta ever again. Yuhata explained that Kobayashi sensed his anxiety over the placenta and wanted him to focus as a pilot. Nagate understood and accepted those words without hesitation. To make up for lost time, Yuhata gave Nagate a jet back so he can quickly fly off to re-join Izana on their outing.

Prototype Launch & Tsumugi's Debut

Some time later, Izana and Nagate were walking together when they bumped into some classmates. They invited him to eat but he declined, citing he's busy. However, Izana would catch Nagate eating on his own. She asked if Nagate was hiding something from her, but he feigned ignorance. Izana knows Nagate is hiding something to his training and proceeds to choke him. Because the intensity of her cybernetic arm is tied to her emotions, she was choking the life out of Nagate. Realizing her mistake, Izana pulled back and apologized. Nagate quickly forgave Izana and excused himself. At the elevator, Nagate bumps into Samari when Sidonia's emergency alarm warned of a gauna heading towards Sidonia. Samari has been suffering PTSD from the previous mission and couldn't sortie; Nagate is taking over.

At the CIC, it's been revealed the ship that's been transporting colonists to the Lem System has been devoured by the gauna and it's now heading towards Sidonia. With Samari unfit to pilot the prototype Type-19 unit, Sasaki was instructed to let Nagate take over Samari's place. As the Toha engineers prepare Nagate for the prototype, Sasaki apologized to Nagate as she had not time to adapt the unit for him and warned the systems are more automated than the Type 18. He is warned the unit isn't like Tsugumori and will not be able to adapt based on his senses. Sasaki gives him the usual warning about not breaking the unit and he's ready to sortie.

Seii's and Tsuruuchi's squad already sortied and both formed a four-unit clasp formation to fly towards the colony ship. Nagate launched last and he's flying solo this time; everyone was surprised at the speed of the new prototype as it out speeded the other units. Outpacing the others, Nagate reached within range and fired his gun. Unfortunately, the back unit malfunctioned and the main engine stopped due to the gauna firing at him. Nagate struggled for control and managed to fire another round, but it didn't hit the true body. Upon investigation, it's been discovered the gauna has created multiple layers of husk within its body to act as body armor to protect itself. Sasaki told Nagate to use the secondary equipment, a machine gun that can fire 36 bullets in full-auto. Although able to rapid fire many anti-gauna rounds, it's only effective at close range. With the booster pack damaged, there was concern it could fly, but Sasaki assured the prototype can still outrun the Type-18s with just its leg engines. With Yuhata's permission, she had Tsuruuchi's squad cover Nagate and provide concentrated fire on one spot while Nagate closes in for the final blow. Everyone acknowledge their roles and broke formation to attack.

The guardians began firing on the gauna while Nagate activates the prototype's secondary combat function to begin close range firing. Nagate still visibly struggled handling the prototype and despite making progress to expose the true body, the placenta was regenerating at great speed. As the gauna returned fire, Nagate lost the prototype's right arm. As the guardians attempt to destroy the assimilated ship, another gauna is arriving at great speed and Yuhata tells everyone to retreat. With the guardians trying to survive the battle, it was easier said than done. The mysterious gauna appeared and fired a particle beam at their target.

The mysterious gauna (Tsumugi Shiraui) fired on the enemy target and exposed took out 20% of its placenta. Tsumugi then charged into the assimilated ship and began tearing it apart, shredding out the placenta to expose its core. Tsuruuchi felt it was an opportune time to strike back while the gauna kill each other and fired his gun. Nagate wanted Tsuruuchi to wait, but his bullet shot through Tsumugi's left side waist. Tsumugi attempted to fly away but gauna's tentacles captured her. Believing Tsumugi to be good, Nagate intervened to help and declared this gauna is not their enemy. When Tsumugi thanked Nagate, everyone was shocked it sounded just like Hoshijiro.

Nagate knew it wasn't Benisuzume and wanted Tsumugi to identify herself, but was attacked by the gauna before explaining herself. The ship-type gauna began changing its body and adapted a hard shelled form, with multiple layers of plating and ribs to shield itself from further gunfire. Tsumugi used all her power and flew in for a powerful drill attack. She pierced through the true body and destroyed the enemy. With the threat gone, everyone is focused on Tsumugi. It was then Kobayashi declared Tsumugi is not an enemy but Sidonia's new weapon and had Kunato explain himself. Ochiai (posing as Norio) explained this is not a gauna but a sentient chimera and Tsumugi introduces herself to Sidonia.

Back at the hanger, Nagate reacted with anxiety when Tanba called out to him. Nagate apologized for the damages on the prototype, but Tanba excused him as he was battling gauna and they'll repair as many times as needed. Tanba then noticed Nagate dislocated his arm while piloting the unit and had medics escort Nagate for treatment. After getting his arm patched up, Nagate hung out with Izana while eating some onigiri. Nagate talked to Izana, wondering about does Tsumugi really have a human consciousness like humans. He expresses pity for a girl born as a weapon to fight against the gauna. Nagate then declares his steeled resolve to wipe out all the gaunas.

At the meeting hall, Ochiai (as Norio) explains about Tsumugi's creation and assures she's not a safety concern to Sidonia. As Tsumugi explains herself to concerned citizens, she was distracted seeing Nagate present. She realized Nagate's arm was injured and asked about his health. When Nagate replied it was nothing serious, Tsumugi started wagging her tail and caused a minor seismic event at the hall. Although she corrected herself and resumed her speech, there were people in the crowd who weren't convinced Tsumugi was harmless and told her to die. Bothered by such prejudice, Nagate goes to visit Tsumugi.

At Kunato Developments, Nagate and Izana goes to visit Tsumugi. Ochiai allowed them to enter and after passing through a maze of placenta, they found Tsumugi in her regeneration tank. Tsumugi wasn't aware she had visitors; she nearly flushed Nagate and Izana away simply getting up from her tank. Surprised to see them, Nagate explained he thought her isolation would be lonely and came to visit her. Tsumugi was happy to see them as she was curious about humans. Curious about human bodies, Tsumugi interacted with the two using her probe and asked permission to touch Nagate. Nervous about the idea, Nagate relented and Tsumugi exposed many tentacles to touch him. Tsumugi wanted to measure every inch of Nagate but it was the most invasive way as her probing touched all of his body parts. After checking out Nagate, he would make introductions with Izana and she also was thoroughly examined by Tsumugi before letting them go. Feeling violated, the two politely left with Tsumugi's gratitude.

Later, Tsumugi hung out with Nagate and Izana on the asteroid section of Sidonia with Norio (Ochiai), observing the Lem System. Nagate was surprised Tsumugi's eyes were able to magnify that far. There's concern that the Ocarina will close in on the Lem System, but Tsumugi felt there's nothing to fear over a small group of gauna. Norio interjected to say the Large Mass Union Ship is a problem because Sidonia isn't powerful enough to beat it. Izana felt since the ship hasn't moved, they could possibly avoid confrontation. Norio took offense to that comment, reminding her the gauna are hostile creatures with vicious minds; they don't have a choice but to fight. Norio explains they must obtain a power to crush the gauna as soon as possible. Nagate agreed that they should fight to destroy the gauna, but Izana wondered if it's possible to peacefully settle with them if they can communicate. Norio felt such thinking is delusional and dangerous as Sidonia went through many perils because of the gauna. Tsumugi interjected to ask for Izana to show her a picture of her cat; she suddenly warned everyone to head back. The Ocarina has revealed itself and preparing already begun launching gauna for an attack.

Sidonia Vs The Ocarina

Because Tsumugi and Norio are already combat-ready, Kobayashi granted them permission to launch into battle first to see them in action. Tsumugi headed towards the Ocarina while Nagate heads to the locker room to suit up for combat and launch. As Nagate was changing, CIC reports the union ship has launched more than 60 gaunas. As CIC continues to monitor the situation, they realized the gaunas are settle a trap for Tsumugi. The 60+ gauna surrounded her and wrapped Tsumugi within their placenta to attack her from within. Meanwhile, as Nagate prepares to launch, Sasaki warns Nagate that this is the last Type-17 unit and not to break it.

Nagate sorties along with his fellow guardians in a 96-unit clasp formation. As the guardians thrusts forwards, sensors revealed the Tsumugi destroyed all the gauna and released herself from the trap, albeit half her body is gone. Enraged by the cruelty of the gauna, Tsumugi disobeyed orders and plan to attack the Ocarina, but reinforcements arrived. Both Nagate and Izana insisted Tsumugi to fall back and she reluctantly obeyed while the guardians fire. Encircling the Ocarina, the guardians already took out 207 true bodies out of 5,000.

As the guardians continue to fire, Nagate asked CIC for Benisuzume's location but they haven't seen it yet. The Ocarina has not retaliated and remain inactive the whole time, but that wasn't for long. After 407 destroyed bodies, the Ocarina began changing form and Yuhata commanded the guardians to back off as they don't know what's happening. The Ocarina moved it's main body into the center and formed a massive particle cannon, preparing to fire at Sidonia. Realizing the blast would destroy Sidonia, the guardians began aggressively shooting at Ocarina's muzzle as it charges. The Ocarina fired and everyone thought Sidonia is done for, but the beam missed. Confused to how the beam missed its target, the Ocarina prepares to fire a second blast. This time though, Nagate charges straight into the Ocarina.

The gauna is about to fire another particle beam when Nagate flew in, preventing the guardians from firing back. Samari commands everyone to pull back and put their faith into Nagate. Inside the Ocarina, Nagate flew inside the cavity and shot whatever gaunas are in his way. He made it to center to find the great true body with the human-like face. As Nagate open fire on it, the true body actually smirked back at him as he fired. To everyone's shock and delight, Nagate won, the Ocarina dissolved into foam. Just as the guardians marveled over Nagate's victory, Izana called for help. The first beam was deflected because Tsumugi used her placenta to form a shield to deflect the blast, but it caused great injury to Tsumugi.

While all the guardians celebrated their impossible victory, Nagte went to check on Izana and Tsumugi. Izana suffered only minor injuries because Tsumugi protected her, but she lost 90% of her body mass. Norio arrived, also injured, but assures Nagate that Tsumugi will recover. Just as the guardians begin to relax after the battle, CIC reports the Large Mass Union Ship has moved. During this time, the Immortal Ship Committee privately discuss matters without Kobayashi.

Fall of The Immortal Ship Committee

The committee learned Kobayashi intends to fight the Large Mass Union Ship and questions her decision; they plan to remove her. The committee is in agreement that Kobayashi is to be impeached and that a new immortal member will become their next leader. Just as the committee moved to have Kobayashi arrested, Ochiai (clone) appeared to object their motion. The committee recognizes the clone, but before they could do anything, Ochiai wiped out the entire committee. Using a special weaponized glove, Ochiai used it like a gun and assassinated the entire committee.

Kobayashi quietly executed her coup and became the sole ruler of Sidonia, without a single person realizing the change in power. Kobyashi felt the committee didn't care about Sidonia and its influence would only make things harder in the future. Because the committee had always operated in the shadows and most of Sidonia unaware of the true hierarchy within their own government, Kobayshi now rules Sidonia unchallenged. During this time, Nagate walks to the dorms with Izana. She suggested they go somewhere to eat, but Lala already plan to make dinner for him. As they continued walking, the lights suddenly went out. A ship-wide announcement is made that their emergency state is at level 10 and the ship may experience emergency acceleration without warning; they must be prepared for gravitational fluctuations. This would mark the beginning of Sidonia battling against the Large Mass Union Ship.

Preparing for Lem-VII & Getting Evicted

At the Lem-VII (Earth-like) planet, the advanced colonists established an outpost and began surveying the planet when the gauna arrived and devoured them all. In response to the Mass Union Ship occupying Lem-VII, Sidonia has begun a large-scale and complex mobilization. It is believed at least 100 of the latest Type-19 Guardians will be used along with Tsumugi to claim victory. During this time, Nagate and Izana heads to Kunato Developments to visit Tsumugi. The two have been worried about the severity of injuries, but Tsumugi has show significant recovery since yesterday's battle.

While heading back to the dorms, one of the Honoka Sisters invited him to sample the new pilot rations, but to her shock, Nagate wasn't hungry. At the dining hall with Lala and Izana, Nagate once again showed a low appetite. While heading to see Tsumugi, Mozuku informed Nagate that Tsumugi has recovered well enough to be transferred back to her regular tank. Excited by the news, he ran to see her regain most of her lost mass. Nagate fell asleep at Tsumugi's tank and began dreaming about Hoshijiro. Tsumugi regained consciousness and found Nagate asleep; she probed his mind while he slept and learned about his feelings for Hoshijiro. When Nagate woke up, it was already morning and he happily embraced Tsumugi for coming back to the living. Izana also arrived and brought her cat for Tsumugi to see. The guardians would later be summoned for advanced pilot training.

Toha Heavy Industries has mass-produced the Type-19 Guardians to take on the Mass Union Ship at Lem-VII. The guardians have been summoned to run training clasp formation drills with their new units; Nagate continues to use his Tsugumori as it has been enhanced and custom-modified to make it comparable to the Type-19 series. At the hanger, the pilots finished putting on their gear and Sasaki remarked that their suits have been altered to combat gauna outside of their units. Tanba remarked their own samurai style blades are also made of artificial kabi to combat the gauna, however, he doubts they would use it for direct combat situations; it's considered more of a good-luck charm. As Nagate prepared to sortie, Tanba informs Nagate that the Tsugumori's chest armor has been enhanced with Megastructure like the Type-19; he also reminds Nagate not to damage the unit because of Sasaki before heading out.

As clasp formation drills begin, Tsumugi appears and impresses everyone with her speed. The squad welcomes her into the fold as they train together. Sasaki also noticed Tsumugi's speed and asked Norio (Ochiai) over the possibility of adapting such speed to the guardians, but Kunato admited he doesn't know how to himself. After training, Nagate was eating the battle rations when Mozuku surprised him. She came to say Tsumugi rally likes Nagate and hope to continue treating them both well.

Sidonia is on their way to Lem-VII and arriving close to Lem-IX. After the decimation of the colonists, the Mass Union Ship flew out of the planet and began orbiting around Lem-VII. Kobayashi has assembled the guardians to review what Sidonia intends to do. She tells everyone that Sidonia is heading to the gas giant of Lem-IX. From there, they will enter orbit with Lem-IX and use the moon cluster as a natural barrier and staging area for attacking the gauna.

At Tsumugi's new quarters, Nagate and Izana was happy that she's got a nice window view. The two felt her new room is smaller than her old one, but Tsumugi didn't mind since she enjoys reading even in a smaller room. After visiting Tsumugi, Izana noticed Nagate being thoughtful and asked what was he thinking. Nagate related to Tsumugi's current living conditions with his past underground life; he wanted her to have a better living experience. Nagate goes to ask Yuhata permission to give Tsumugi the chance to visit the living quarters, but she absolutely refused. Nagate decided to go around Yuhata by exploring the tunnels with Izana. It was while climbing through a tunnel that Sidonia fired its retro-boosters to slow its descent to Lem-IX. The suddenly shift in gravity caused them to fall upwards and back down. Nagate managed to grab hold of the ladder and Izana used her legs to hold onto Nagate. However, Izana clamped so hard that Nagate's face was turning purple.

The duo survived the gravity shifts and ended up outside of the massive tubing. The two found a specific port to open and it allowed Tsumugi to use her probe to snake all the way to a scenic view of the residential zone of Sidonia. Tsumugi admired the view and wanted to be human-size to meet the people there. Izana tells her that there isn't a person that doesn't know about Tsumugi's heroic deeds, but Tsumugi excused herself to continue admiring the view. Heading back to the dorms, Nagate finds his stuff outside of his room and finds a new cadet occupying it. Nagate totally forgotten that he's no longer a cadet anymore and has to move out. Officially homeless, Nagate seeks Izana for temporary housing.

At Izana's home, Nagate expressed his gratitude for letting him stay; Izana felt it was good timing as she kept hearing strange noises and feels uneasy at home. Curious about Izana's grandmother, Izana remarked she's too busy as of late to come back home. While making some onigiri for Nagate, Izana heard a rumbling sound again and it was freaking her out. Izana finished making the onigiri for Nagate when she tripped on a loose floor board. Nagate leaped to save Izana from a hard fall and saved the food when the two freaked out over a creature coming out of the floor, it was Tsumugi. After realizing it was Tsumugi, the trio calmly sat together to talk. Tsumugi has felt lonely and ventured out to see her friends; Nagate welcomes her to see them any time she wants. The two would sleep over at Izana's for the night. Unknown to the three, Yure has been working with Ochiai to bring forth another chimera: Kanata.

House Hunting & Living with Izana

Nagate headed to the Administration Bureau of Housing to look a new home. Speaking with the admin, he asked for her help to find a lodging filled of old plumbing. Showing what he's done so far, he asked for an unpopulated place near the outer wall. Shocked, the admin has never encountered someone with an unlimited residence permit nor shown anyone to an outer-wall lodging. The admin goes searching the information for him while speaking of her envy of Nagate able to live near the outer-wall. The admin gave Nagate a lead that suits his needs and he later accepted it.

Back at Izana's home, Izana offered Nagate to live with her as her home has a spare room. Nagate thanked Izana, but he already has a new home. Showing the diagram of his new home, it's a lodging that's close to Tsumugi's Room and plenty of old plumbing to let Tsumugi visit. Nagate asked Izana to live with him, but she shredded up the diagram while informing him that not everyone has permission to live at the outer-wall. Nagate nervously inform Izana that it won't be a problem as he's allowed to take one housemate on his (shredded) authentication. Nagate thought Izana was mad, but she quickly accepts.

The two would take a long hike up to their new home as they traverse through long and high stairs to the outer-wall. Izana was worried it is far from the station, but Nagate tells her there's an elevator that takes them directly to base if they are called to scramble. Once at their new home, Nagate calls Tsumugi and warns Izana to old her breath due to the pressurized pipes and dust. Tsumugi suddenly appeared and blows out all the dust from the old apartment; it caused a massive dust cloud and the two chokes on it. Tsumugi apologized for the dust cloud, but Nagate didn't mind as new place needed to be dusted out. Nagate wondered about Tsumugi's experience in getting here and she remarks the tunnels are big enough for her to snake through without a problem.

New Toha Developments & Heroic Mockery

At Toha's research and development lab, Nagate was invited to test out a new prototype cockpit. The engineer was curious about Nagate's experience and he felt the controls resembles Tsugumori's system and even easier to control. The engineer remarked the cockpit is like that because it's a direct successor to the Tsugumori. As Nagate headed to testing ground to see the new parts and admired the beauty of the material resembling ceramics. The engineer also showed how light and strong the material is, but because of the difficulties in making it, the production cost is 100 times more than the Type-18. He also reflected the frame is capable of withstanding the heat of a star, but pilot would unlikely survive. Just then, Tanba called for Nagate to check out their new support craft: the Hayakaze.

Tanba introduced the prototype Hayakaze. It's a autonomous support cuirass for the guardians and Nagate remarked it's big. Tanba explained it was designed to dock four guardians inside it's armored compartment and Nagate marveled at the idea of combination. Just then, a female pilot wondered is the tip of the cuirass fitted with artificial kabi. Tanba confirmed it and the pilot remarked it's more of a coffin made to execute a suicide attack against the gaunas. Tanba remarked he heard that the development of the High-Cost Unit's Prototype has slowed down Type-19 production and the Type-18s were extended for service. The female pilot angrily remarked since the Type-19s aren't coming for pilots like them, they should just board the cuirass and ram into the gauna. The pilot's friend tried to excuse her words due to anxiety for the upcoming mission; she remarked the recon mission will be done by a Type-18 and that the captain wouldn't risk state-of-the-art units or elite pilots on potential gauna traps. She walked away mocking how great it is to be a favored hero and she'll sarcastically count on him as she left and laughing. Tanba tried to tell Nagate not to be affected by her words as he doesn't want to see an emotionally distracted pilot.

Back at his new home, Nagate was in deep thought when Tsumugi arrived, noticing his depression. Nagate wondered why Tsumugi haven't slept yet but her body doesn't require sleep but can easily go to sleep if she wants. Nagate found a Stag Beetle and Tsumugi took the time to observe and touch it before it flew away. Nagate felt tired and decided to go to sleep; Tsumugi wanted to sleep with Nagate. The two would awkwardly sleep together with Nagate wide awake. The following morning, Nagate got some rice and natto when Yuhata called for Izana. The same pilot that mocked Nagate yesterday renounced the mission and was arrested; Izana has been called to replace her.

Rescue at Lem-IX & Defeating Benisuzume

At the CIC, Yuhata informed the recon squadron that they'll launch, dock with the Hayakaze, travel to Lem-IX, survey the sector, and immediately come back. Izana and her squad managed to dock with the Hayakaze and head to Lem-IX without a problem; both Tsumugi and Nagate are worried and wanted to go with her. The recon squad made it to the Saturn-like planet and began flying through the planet's ring. As soon as they flew through the ring, Izana used her cybernetics to scout for any signals and suddenly detected gauna contacts heading their way. Yuhata commanded the team to immediately head back to Sidonia. However, as they flew, they detected something and fired upon the it to reveal a cloaked gauna.

There was a massive gauna that has been hiding within invisible placenta. The recon squad quickly stopped Hayakaze and decided to break off while launching the kabi tip. The inertial launch failed and the gauna destroyed unit 2. The surviving guardians attempted to join in a clasp formation for a quick escape, but the gauna caught up and started killing everyone. Izana reacted fast and managed to save a fellow pilot, but his unit was destroyed in battle; she risked saving him and got pulled down by the planet's gravity. Watching Izana crash was hard for Tsumugi to watch and she wants to go save her. Nagate requested permission to go rescue Izana, but a pilot doesn't reserve the right to choose their missions. Norio (Ochiai) convinced Kobayashi to allow Tsumugi sortie along with the new High-Cost Unit's Prototype to gather combat data before taking on the Mass Union Ship at Lem-VII. Nagate and Tsumugi both sortied and headed to Lem-IX to rescue Izana.

While flying to Lem-IX in clasp formation, Nagate checked in with base to see did Izana contact Sidonia; Yuhata replied that communications are still down and their situation is unknown. Tsumugi reminded Nagate that all they can do right now is to have faith and fly to their rescue. Meanwhile, Izana entered the planet's atmosphere to evade the gauna, but they continue to pursue. She managed to eliminate some of them while descending, but realized she's running low on bullets. Realizing the gauna are attracted to the artificial kabi and the particles from her unit, she emptied whatever she could to reduce the gauna's attention and it worked. However, she still went through a rough crash landing as she reached the ground.

Near Lem-IX, both Tsumugi and Nagate made it to the planet. The two decided to enter the atmosphere from high orbit to avoid getting trapped by the gauna. As the two are about to prepare for atmospheric entry, Tsumugi detected gauna and the two broke formation to fire at them before resuming formation to descend. Tsumugi suddenly detected something, before they could identify the signal, the High-Cost Unit's Prototype was shot down and crashed onto one of the floating islands. Fortunately, the prototype's frame is strong and didn't suffer major damage. Nagate wanted to look for Tsumugi, but only had a piece of her right hand when it was severed. He eventually found Tsumugi engaging a red gauna in aerial combat. The gauna stopped long enough for the two to realize it's Benisuzume. As the two battled, Tsumugi encouraged Nagate to go search for Izana. Mozuku assures Nagate that they are superior to Benisuzume and he left to find Izana.

Meanwhile, Izana and the surviving pilot left their damaged units and began traversing the land. It wasn't long the two were being chased down by a humanoid gauna and Nagate managed to spot them. He fired upon the gauna as the two ran to a cliff and fell; Nagate flew down and managed to catch them. However, the prototype's presence has attracted the other gauna as well. Nagate placed the two pilots in the prototype's compartment and began to fleeing as he can't battle them in atmosphere. With many gauna coming, he decided to anchor the unit to the ground as a firing solution. He managed to shoot down many gauna, but he ran out of bullets. With three remaining, engaged the remaining targets with his anti-gauna blades to cut them down. Nagate managed to re-establish communications with Sidonia and everyone was impressed by the prototype's performance.

Nagate then flew back to find Tsumugi. She had defeated Benisuzume and was about to eliminate what remains of her when she lost nearly all her power. Benisuzume launched a surprise attack by turning her damaged body into a needle and siphoned her particles. With Benisuzume completely recharged and Tsumugi weakened, the gauna was about to kill Tsumugi when Nagate charged in and grabbed Benisuzume. Nagate managed to drag Benisuzume through the surface and the head unit got damaged during the struggle. While the true body was exposed, Benisuzume used her placenta to seep into the cockpit. Reforming into a naked Hoshijiro, Benisuzume restrained him. Izana reached out to Nagate, to tell him to shut down the airframe's neck air-lock to block the placenta from penetrating the frame; he couldn't reach the controls. The placental Hoshijiro began choking Nagate. As Nagate struggled for air, he told the gauna to stop imitating Hoshijiro; it proceeded to kiss Nagate with her tendril tongue. During this time, Izana used her cybernetic interface to shut the air-lock and severed the placenta's connection to the main body. The placenta backed off just enough for Nagate to grab the controls to stab Benisuzume's true body and finally vaporized it.

After confirming Benisuzume's defeat with Sidonia, Nagate went to check on Tsumugi. He used to the prototype to carry her to a clearing and transferred some of his particles help her fly again. Due to the opportunity of recovering the placental Hoshijiro, Yuhata had Nagate fly back with the naked gauna within his cockpit. Once the prototype returned to Sidonia, the engineer directed Nagate to head towards a special decontamination chamber. Placed into a massive liquid tank, the machines removed the placental Hoshijiro while clearing out remaining placenta from the unit. After clearing from decontamination, Nagate couldn't help think about Hoshijiro.

While walking at the residential area, Nagate saw the ad on Gravity Noodles and wanted to try one out. He got home and no one was around; he decided to try out the gravity noodles. Nagate was savoring the noodles when Tsumugi appeared before him as Hoshijiro. Nagate was so taken back that he spilled all the hot soup onto his lap and yelled at Tsumugi. Angered by this stunt, he warned her to never do that again and slammed the door back to his room. After Nagate's anger settled, he felt bad and went to see Tsumugi. She was in tears because Tsumugi wanted to cheer Nagate up. She knows that Nagate has been feeling guilty over Hoshijiro's death and thought by taking her form and forgiving him, he would feel better; it backfired. Nagate overheard their conversation and appeared before the two; he apologized for shouting at Tsumugi and suggested a sightseeing trip nearby and the trio agreed to go.

Izana's Transition & Sidonia Vs Gauna Bullet

Sidonia Command would call forth their pilots to suit up and be on stand-by alert status. Nagate didn't see Izana and he went looking for her. Izana has been having trouble with her suit due to the fact her body fully transitioned into a girl. The suit didn't recognize the bodily changes and rejected Izana's commands. Nagate looked for her and found Izana still struggling with her suit. Nagate also thought the situation was odd as the suit mentioned irregular repairs and wondered did Izana make any modifications. Running short on time, Nagate told Izana they had to go and she hacked into the suit to accept her commands, forcing the suit to over tighten on her body. When Sidonia went on reverse trust, Izana quickly grabbed a handle when her suit ripped, exposing her new body. Nagate was surprised but was suddenly pulled down the hallway from the inertial shift and broke his neck.

Later at home, Nagate was eating when Tsumugi noticed him wearing a neck brace. When she asked about it, Nagate simply said he fell and he'll recover soon. At the hanger, it's been revealed Toha has mass-produced a large number of Type-19 units, but still less than half the target number. The new guardians were launched to Lem-IX for training, while everyone struggled to adapt to gravity conditions, Nagate and Tsumugi already adapted to the gravity.

At home and resting, Yuhata came the visit and Nagate quickly told Izana; both wanted to hide Tsumugi but she personally opened to door. While sitting down on the counter table, Yuhata didn't make it a huge matter over Tsumugi's presence at Nagate's home. Tsumugi asked if she could explore the residential area and Yuhata denied her, only allowing her to hang with Nagate. After being invited by Izana, Yuhata stayed for the night and learned about Izana becoming a woman. Nagate was eating his gravity noodles and could hear their conversation upstairs. Nagate overheard that Izana found her male partner and Nagate spat out his noodles from the shock. When Izana walked up to Nagate, she realized he overheard everything they said from the bathroom. As the overhear Tsumugi and Yuhata talk about playing card together, Izana nervously declared she won't be playing cards with Nagate as she slammed on the table hard. She hit the table so hard that the soup jumped out of the cup and splashed all over Nagate.

After running a training session with rookie pilots, Tsumugi, Izana, Yuhata, and Nagate spent the night together watching a movie. While sleeping, a tactical alert was made and everyone had to get ready for combat. At the command center, sensors has revealed the Mass Union Ship has fired a singular probe with one true body, a massive gauna that's heading for Sidonia. They believe the it's a living high speed projectile that can adjust its course and it's going to destroy Sidonia through sheer kinetic force; Tsumugi and Nagate were informed of the situation and launched to intercept it.

The duo were given a new prototype cannon to fire upon the approaching target. Unfortunately, the placenta was too think and it didn't hit the true body. Other guardians were called to fire it with kabi rounds and firing at the gauna with their cuirass spears. Taking a gamble, Yuhata had the incoming gauna get closer and fired a rail round from Sidonia. The mass of the shell exposed the true body within the center. Tsuruuchi made the victorious shot and defeated the gauna, but at a cost. Sidonia was caught within Lem-IX's gravity and was forced to use its thrusters to restore a stable orbit. During that time, certain structures fell apart, causing casualties. Yuhata fell from the gravity and Izana cushioned the impact with her body, but left her injured.

Back at the hanger, everyone was taking a breath and celebrating their victory. As Nagate went to see Tsuruuchi, Tsumugi offered to help him photosynthesize and blasted both of them with intense UV light. Worried about Izana, Nagate ran to see Yuhata to learn about her situation. Nagate learns Izana's grandma is personally treating her and assured she'll be fine. Nagate and Yuhata waited at the treatment theater until Nagate fell asleep on Yuhata's lap. Yure came out to report Izana will recover. As the two walked home, they noticed it's snowing and Yuhata remarked that winter might be a fixed season to reduce particle consumption until the gauna conflict is over.

The 2nd Chimera Project & Explosion Coverup

At the hospital visiting Izana, Nagate opened a tubing to allow Tsumugi to probe her way through to see her. Nagate and Izana tried to hid Tsumugi when Yuhata arrived. Unknown to them, Ochiai has created another chimera: Kanata. Curious about Sidonia, Kanata has been exploring the ship through the pipes just like Tsumugi. However, the Honoka Sisters spotted Kanata coming out of their shower and freaked them out. Yuhata doesn't know about Kanata and presumed Tsumugi risked exposing herself; she warned Tsumugi to be careful with her exploration from the local residents.

After Izana recovered, Nagate took her home. Worried she'll slip from the frosted stairs, he held her hand as they walked back home. Back at home, Tsumugi escorted Izana to her room, surprising Izana that Yuhata and Tsumugi had converted it into a Kotatsu Room. Using the winter and energy savings as an excuse, Yuhata formally declared she has moved in with them and already taken a room right next to Nagate's room (much to Izana's dismay). While the girls enjoy their kotatsu, Nagate was eating a cup of gravity noodles when the Honoka sisters arrived.

Ever since that horrible encounter with Kanata in the shower, the two sisters decided to hunt for it and managed to detect Tsumugi's signature to Nagate's home. Surprised to find the sisters here, the two barged in and straight into the kotatsu room. Izana and Yuhata pretended to fall asleep when the sisters charged in, tossed out the kotatsu, and stabbed the pillow. Pretending to be surprised by their arrival, the sisters explained that they're hunting for the tentacle monster. They believed they're hunting for a forgotten edible insect 300 years ago that has been resurfacing through the old plumbing. Tsumugi appeared before them, taking the image of the monster and scared the sisters out of the house. The trio were happy to get rid of their unwelcomed guests but Lala called them to have words about the kotatsu that crash landed on her property.

While watching the Honoka Sisters repair Lala's property, there was a sortie call. There has been a faint signal and Tsumugi and Nagate went to investigate, but nothing was found and they returned to Sidonia. While playing cards with the girls, Tsumugi detected a gauna signal. During this time, Tsumugi's unknown sibling, Kanata, as gotten out of control while a gauna has latched itself on the surface of Sidonia, exponentially growing larger to attack the ship.

Guardians were dispatched to handle the invasive gauna while the senior ranking members struggle to regain control of Kanata. The gauna was created with a Graviton Radiation Emitter and when Kanata became unstable, she fired the emitter. The attacking gauna sat right above where Kanata is located; when she fired the beam, it took out the gauna, a guardian, and damaged a nearby moon. By the time Nagate and Tsumugi arrived, the situation became manageable. Kanata's existence was covered up and the incident was written off as a gauna attack. Despite Yure's report of Kanata being unstable, Kobayashi risk the continuation of the 2nd Chimera Project to further develop anti-gauna weaponry.

After Kanata's incident was successfully covered up by senior members of Sidonia, the guardians and Tsumugi were tasked to assist in repairs. Being part gauna, Tsumugi was able to fly effortlessly in space and she zipped through the construction team with ease. When she accidentally knocked over a series of panels, she went to sulk about the matter. Nagate arrived to comfort her, seeing her feeling bad about the situation. Surprised Nagate can read her expressions, she ran off in embarrassment.

Some time later, Izana went to see Yure and the two decided to hang out at a café. Yure had some old provocative dresses and convinced Izana to dress with her like twins for fun. Unfortunately, Yure had to leave and Izana was stuck in the open in her white dress. Her greatest fear is to be spotted by her friends as Nagate called right behind her. Mortified it had to be Nagate, Izana walked back home with Nagate; her dress made things uneasy. The two decided to visit Norio to see if he's recovering, but Mozuku mentioned he hasn't regained consciousness at all. Disappointed, the two returned home to find Yuhata mad at Tsumugi for ruining her gunpla assembly.

Suicide Date with Izana

Nagate and Tsumugi had a great flight exercise together and Tsuruuchi just had to joke the two flirt while working and it got on Izana's nerves. Back at the hanger, Nagate wondered if Izana sortied today and Izana snapped at Nagate. She told Nagate she was working with them the whole time, tailing behind them the whole day but felt Nagate was too happy to notice her and stormed off. Nagate was confused why Izana was mad but Yure knew her granddaughter's heart and decided to do something about it.

Yure summoned Nagate to perform a secret mission: perform a cultural research project. An arranged date set up as a false mission, Nagate believed Yure's assignment is for real and wasn't sure how to navigate his way to the sites; Yure gave an "exception" for Izana to tag along to help him complete his task. Nagate wanted to know more about this research aspect, but Yure silenced his curiosity and even lied about implanting an explosive in his body (when he broke his neck) to motivate him to take the job without question. To avoid getting Izana mad, Yure made it clear Izana must not know the mission came from her. Shocked and scared, Nagate headed home to get Izana for the mission.

At home, Nagate went to Izana's room to explain his situation to her. The two are given an exemption for 2 days for this "mission" and accommodations have already been made. Izana was touched, believing this to be a romantic trip, but Nagate made it clear it's a serious matter (motivated by the false bomb in his neck). Nagate was worried Izana wouldn't accept due to her aversion to bugs, but Izana accepted and the two prepare for the trip.

The following morning, both Izana and Nagate got up early in the morning to begin their excursion. Nagate excused himself out by saying he had something to do while Izana lied about going out to visit Yure. Both Yuhata and Tsumugi overheard their conversation and knew what they were up to, but still played ignorant about the matter. Both were surprised how the two could lie about their intentions so easily.

While observing Sidonia's only sakura tree, Izana was enjoying the scenery while Nagate strictly and thick-headedly followed through Yure's instructions. At a scenic park, Nagate continued to follow Yure's commands and intend to await further instructions until midnight. With nothing in mind, Nagate asked Izana what they should do until then. When the two realized they're at a secret hot spring, Nagate was excited and thought about inviting Tsumugi next time. Irritated at the mention of Tsumugi, Izana suggested they should try taking a bath together. Izana grabbed Nagate's hand and caught his pad. She quickly realized the mission was from her grandma and leave. Nagate tried to deny it but Izana was infuriated and thought this whole outing was cruel. When Nagate tried to stop her by grabbing her cybernetic arm, she resisted and caused serious injury to Nagate's face. While in a wrestling struggle together, Izana told Nagate he doesn't care about her. However, Nagate honestly denied this and made it clear he absolutely cares about her (albeit platonically).

Tsumugi's Date with Nagate & Nagate's Confession

Before the major operation to take a ship mass union that is within LEM-VII, Nagate Tsumugi asked to spend the whole day with him. Never once able to venture within the limits of Sidonia with his real body, Nagate obtained permission for the two to fly in Sidonia; he plans to visit the interior of Sidonia with his Tsugumori Custom 2 unit with Tsumugi. Nervous and excited, Tsumugi was able to get an up close and personal view of the residential area of ​​Sidonia and tried going to the beach for the first time. It was when on the beach Nagate made his declaration of love for Tsumugi.

Nagate Tsumugi said he hopes to have more experiences with her and touched her, tearfully. Surprised she would start crying, Tsumugi admitted that she always wanted to be seen by him as a normal sized girl. However, Nagate did not care that she is not human and the difference of 15 meters in size. He told her that he wanted to live as long as possible to be with her and confessed I like you Tsumugi!

Shocked by the confession of Nagate, Tsumugi passed over high heat in artificial seawater. So overwhelmed that his contact with the sea actually evaporated some of the water and the burning steam Nagate. They sealed their relationship with Nagate kiss her and the two spent the remaining time floating in a happy nap together. Unfortunately, Ochiai inconveniently interrupted his time as he finally reveals himself back to Sidonia.

Kanata Escapes & Second Revolt of Ochiai

Kanata is Tsumugi younger brother chimera. However, its existence has so far been kept secret and known by few in Sidonia. Ochiai, Norio within the body, used his experience in creating Tsumugi to create Kanata, but chimera proved challenging and almost caused a previous incident; it was considered too dangerous and uncontrollable. Higher functions of Kanata were stopped with a controlling interest and Sidonia command had planned for dismantling until Ochiai intervened.

Secretly, Ochiai learned where he went wrong with Kanata and already had the solution to correct Kanata; he chose to use this as your opportunity to escape instead. Although Ochiai taking advantage of Norio body and using Kunato Developments, he felt it was time to go as it has everything you need to survive on their own. Having planned his departure ahead of the safety of Sidona he had enslaved Mozuku Kunato help him escape by sabotaging Tsugumori Custom 2 and kill whoever was on his way to his escape. As Sidonia Command was about to dismantle Kanata, Ochiai made his re-appearance boldness and fled with Kanata, not once, not even informing Tsumugi of the situation. Both Nagate and Tsumugi now launch to avoid Ochiai's calamity.

The Battle of Lem-VII

An operation was started by Captain Kobayashi to attack the large mass union ship orbiting Lem-VII with the use of three fleet Mizuki ship of the type with two carrying them emitting experimental gravitational beams. Izana is placed in recon fleet, Yuhata in the first round fleet, Nagate gets back until your new type 20 Yukimori is complete, and Tsumugi is placed with the second assault fleet. As the operation proceeds, the second assault fleet is intercepted by a mass Union ship that overshadows the fleet, and the guardians and Tsumugi are deployed to defend the emitting gravitational radiation. however, during the battle, a huge particle beam Higgs, who was fired from the ship mass union, hit the emitter, causing an explosion that takes out the entire fleet, the ship mass union and everyone in it. It is suggested that there were no survivors, and at the end of chapter 68 shows all that remains of Tsumugi was she mutilated tail up. However, in chapter 72, it is revealed that Tsumugi is alive with a ship from the second assault fleet, although in critical condition. Upon arrival in his new Type 20, Nagate resolves to make his own with the first assault fleet where it can be submerged in a tank for more intensive healing.

Defeating Ochiai & Losing Tsumugi

After Nagate left her with the first assault fleet to recover, he sped towards the Star Lem to face Ochiai and recover the converter. The battle would be difficult due to the fact Ochiai intentionally carried out a controlled distance near the Star Lem, which makes it difficult for anyone to reach it as many might not withstand the intensity of the heat. Ochiai also entirely covered in Kanata megastructure, making it almost impossible position for anyone to get beyond Yukimori.

Nagate gave chase through the hell of the star, attacked Kanata and parts of itself that Nagate can effectively damage through its exposed shield. The battle took a toll on Kanta's body and Ochiai could not heal Kanata fast enough to make a difference in the fight. Selfishly defiant to the end, Ochiai still believed that it is essential for the survival of humanity, even at the price of Sidonia. Nagate finished Ochiai, destroying Kanata, vaporizing what's left of the chimera and killing Ochiai.

Although victorious, Negate's victory was only temporary. Yukimori's environmental control systems' s been compromised during the battle; the unit is unable to seal properly away from the intense heat and Nagate being burned alive inside their cockpit. Because Nagate is an immortal, he was able to tolerate extreme temperatures to a degree, but his skin was already boiling from the extreme heat. He regained the converter and tried to fly through the heat even though he knew there was a possibility that he will not survive. Nagate put Yukimori on autopilot, because he knew that although his body can not do it, the unit can survive the extreme heat and still deliver the converter to the first assault fleet to complete the mission. Although everyone knew that it would mean the death of Nagate, everyone expected that he could survive through this like he always did in the past. Nagate would survive, but at the price of Tsumugi.

While curing inside the tank, Tsumugi was aware of the situation and decided to save the man she loved. She only partially recovered from his battle and was not physically fit to sortie, but she blew a hole through the ship to escape and immediately rushed to the aid of Nagate. Using her own body, Tsumugi covered up Yukimori, giving the unit a chance to cool off. Nagate was strongly against the actions of tsumugi and tried to convince her to go back, but she stayed with him as she slowly vaporized. In her final moments, Nagate held Tsumugi and she said Tanikaze-san, I was happy to be born in this world. Thank you. Tsumugi was completely vaporized to the horror of Nagate but Sidonia still had priority. He made it back to the assault fleet and delivered the inverter to drive the gravitational beam and pulled the mass union ship in Lem-VII; Sidonia won, but at a terrible price.

Reconstruction After Lem-VII Return & New life for Tsumugi

The battle for Lem-VII is long and Sidonia had won at a terrible cost. The front section of Sidonia was devoured by Gauna, exposing the ship and its inhabitants to the elements of outer space; engineers raced to contain the damage and restore Sidonia. Nagate could not return home because of the damage caused by the battle; he and Izana had to live in temporary shelters until they can find permanent housing. Two engineers came to give Nagate a burnt fragment Tsumugi curtain. All Sidonia knew loss Nagate and people offered their condolences and assistance to help Nagate feel better, but would not bring back Tsumugi. In between, Kobayashi announced the formal victory over Gauna to raise morale, but due to particulate contaminants placental Lem-VII (after destroying the ship orbiting mass union), there were serious concerns was the planet habitable.

A month passed and Nagate has since fully recovered from his burns. Engineers Sidonia created an emergency lid on what's left of Sidonia at least restore the artificial gravity and environmental controls. The Yukimori was also finally repaired, but none of that mattered to Nagate as he still cried for Tsumugi. While getting emotional about Tsumugi curtain, he was shocked that the Hoshijiro body falls into his arms, is Tsumugi.

It was originally thought that Tsumugi died trying to save Nagate Star Lem, however, an evil-living worm fragment of her survived into the inner of Yukimori. Yure Shinatose at the time managed to reverse engineer the Ochiai deceased's personality transfer technique and decided to merge the Benisuzume Hoshijiro with what's left of Tsumugi. The process worked and successfully brought Tsumugi and Hoshijiro back to Nagate.

The Benisuzume Hoshijiro still kept the memories and experiences of the original Hoshijiro. However, after the personality transfer and Tsumugi memories in the same body, he created a new person, doing Tsumugi and Hoshijiro into a single entity. While still technically part Gauna, Tsumugi new body is more humane than Gauna; it can never regain their former body for anti-Gauna combat.

Although she finished her new body, Tsumugi was eager to see Nagate. Still new and adapting to her body, she got her way to the roof where Nagate despaired about her "passage". She stumbled right into Nagate and she was identified and they were happily reunited.

10 Years Later & Bidding Sidonia Farewell

Nagate and his family

A decade has passed and half of the Sidonians have now settled upon Lem-VII. The original reason why Sidonia has fought so hard for the Lem System was to establish a permanent colony to insure the survival of humanity. After the last great battle, Sidonia successfully vaporized the giant Mass Union Ship that orbited right above Lem-VII; the Gauna particles contaminated the entire planet, placing concerns that all their hard work and sacrifice was for nothing. However, Tsumugi simply said it was okay to settle and half the surviving Sidonians trusted her word to settle regardless of the potential fears.

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Their faith in Tsumugi was rewarded as the Gauna particles somehow encouraged the planet to become more Earth-like, making the planet even more human-friendly to habitat. Tsumugi is now married to Nagate and the two have a daughter together, Nodoka. Although originally taking the body of the Benisuzume Hoshijiro, her body changed in appearance after the fusion process, giving her a unique look amongst her peers. Tsumugi herself has lived on the planet with Nagate, where she helps him on his environmental development projects. However, upon this day, it's the day Sidonia leaves once more.

Today marks the day when the remaining half of humanity will settle upon Lem-VII, while a smaller group will remain with Sidonia to discover new worlds and systems to help spread humanity. Both Nagate and Tsumugi came to bid their friends farewell as Izana and Norio will be part of the new expedition team. As the family stood together over the stars, they watched Sidonia depart to new adventures.


Hiroki Saitou
His grandfather, and unknown to Nagate, a cloning source. Hiroki raised Nagate to become an ace pilot. They had a good family relationship.
His legal guardian. They rarely meet, due to their positions, but she knows the origin of Nagate and sympathizes with him. Nagate is one of the few members of the crew Sidonia recognizing their appearance unmasked.
Izana Shinatose
She was the first to get along with Nagate. He sees Izana as a dear friend. They share a house on the outside wall of the vessel after Nagate becomes a squad leader. Izana is interested in Nagate, eventually becoming a one-sided love, as Nagate remains oblivious. They support each other all the time. When Izana was in an extreme situation during an ambush reconnaissance mission, Nagate ordered and carried out a rescue mission consisting only of him and Tsumugi, despite being a planet's distance away.
Shizuka Hoshijiro
Nagate saves her from certain death, ignoring orders from command, and pursued her escape pod beyond the point of no return after Shizuka's Guardian is destroyed due to an engine malfunction while in a sortie. Both developed feelings for each other after being stranded in space for 3 weeks. They had an intimate moment in the proto-aquarium until her uneventful last sortie. Shizuka eventually died protecting an unconscious Nagate from a Gauna during a battle sortie due to the petty acts of Kunato. Nagate having yet to move on from her death, always getting hung up by the mention of her name, even if he does not express it directly. He suffered greatly from the presence of Benisuzume, even though he eventually defeats it, and his frequent visits to the placenta-clone Hoshijiro although he warms up to it until its transfer to Kunato Developments by the now possessed Kunato(Ochiai).
Tsumugi Shiraui
Nagate was the first person to accept Tsumugi. Since she was born from cloned Hoshijiro-placenta, which was fixated on Nagate, she inherited some of this feature as well. She loves him more. Despite her heritage, she is kind and understanding. Currently, she "lives" with Nagate and the rest of the group, winding the probe through ancient building pipe systems. They also become sorties partners after Nagate received his usual Garde. Eventually, though, Nagate chose to have a romantic relationship with Tsumugi, despite their biological differences.
Yuhata Midorikawa
She has feelings for Nagate too. Initially his junior, she was quickly promoted to become his commander. During battles, she maintains the security of Nagate a priority. She also tries to make time alone with him, whenever possible, but her plans backfire usually through unexpected situational developments. She currently resides in a house on the outside wall with Nagate and the rest of the group.
Norio Kunato
Norio immediately recognizes Nagate with his rival after Nagate is allowed to pilot the Tsugumori unit instead. Norio acts bitterly for Nagate and his friends, going so far as to sabotage Nagate during an attack on Gauna, resulting in the death of Hoshijiro. When Norio decided to retire from driving, Nagate visited and tried to convince him to reconsider. Norio despite adamant about this, filled with secret tears. Nagate still on friendly terms with him, even though he is unaware of the transformation of Norio.
Honoka sisters
They all respect Nagate as a skilled pilot and leader. Some of them still have feelings for him, but are subtly shown, such as En and Ren. He treats all of them kindly, but has a tendency to trip over them while they are naked, calling her anger.
Mechanical Nagate unit. It is hard on him for always returning to his unit all torn, but supports it with with some of the best mechanics and equipment available. Because of this, he is afraid of irritating her. On the other side of the coin, it is physically very affectionate with him when praising him, making it difficult to Nagate to be around her when she is feeling happy with it.


Notes & Trivia

  • Nagate riding conditions to demand their participation in every battle. Norio is one of the few members of the regular crew know that condition, and considers it a death sentence against Nagate. Lala with Kobayashi speculated that the Immortal Ship Committee wanted him dead because they could not accept another member of the immortal crew that was not also part of the commission.

Articles and References


Knights of Sidonia Characters
Gardes Pilots

Nagate Tanikaze | Izana Shinatose | Shizuka Hoshijiro | Honoka Sisters | Mochikuni Akai | Hinata Momose | Kashiwade Aoki | Izumo Midorikawa | Eiko Yamano - Toutarou Yamano| Samari Ittan | Tonami | Kouichi Tsuruuchi | Ichirou Seii | Norio Kunato | Kaoru Hazama | Ryouhei Kasuga | Kujira Negi | Hamagata | Hashine | Suzuki

Sidonia Command

Yuhata Midorikawa | Ryouko Takahashi | Ichirou Seii | Ochiai Clone

Immortal Ship Committee

Kobayashi | Lala Hiyama | Hiroki Saitou | Yure Shinatose | Ochiai

ET Research Center

Numi Tahiro | Yure Shinatose

Toha Heavy Industries

Sasaki | Shinsuke Tanba | Shijimi

Kunato Developments

Norio Kunato - Mozuku Kunato


Teruru Ichigaya


Tsumugi Shiraui - Kanata

Gauna 487 | Gauna 491 | Gauna 492 | Gauna 493 | Benisuzume | Placental Hoshijiro | Ocarina | Gauna 541 | Large Mass Union Ship | Lem Gauna Wall | Lem VII Gauna | Aulos
Knights of Sidonia
Anime Season 1 (S1 compilation film) | Season 2 | Love Woven in the Stars
Manga Volume 1 | Volume 2 | Volume 3 | Volume 4 | Volume 5 | Volume 6 | Volume 7
Volume 8 | Volume 9 | Volume 10 | Volume 11 | Volume 12 | Volume 13
Key Subjects Sidonia | Gauna | Gardes | Technology of Sidonia | Characters of Sidonia