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Tsumugi Shiraui (白羽衣 つむぎ Shiraui Tsumugi) was a Gauna-Human hybrid, a Chimera, created by Ochiai and Kunato Developments for fighting against the Gauna. Though secretly she was made from the placenta of Gauna 491 in the form of Shizuka Hoshijiro by impregnating 'her' with a human embryo. At the end of last Gauna War, she married Nagate Tanikaze and settled in Lem VII, where they had a daughter named Nodoka.

Character & Personality

Tsumugi was created as a bio-weapon of mass destruction by Ochiai (possessing the body of Norio Kunato) with the resources of Kunato Industries. By combining Gauna 491 with a human embryo, Ochiai perfected his Gauna-human experiments that he failed nearly a 100 years ago. The end-product was a chimera with enough destructive power to destroy a Mass Union Ship, but serves the interests of Sidonia.

Despite being a stunningly powerful monster, Tsumugi has the heart of a young girl. She's playful and kind-hearted, fascinated even by the most mundane things, and enjoys exploring the world of Sidonia. It is hinted, that her personality is actually remnants of Hoshijiro's own personality through her mother. Tsumugi even sounds like Hoshijiro when she talks, although it is not confirmed, whether she is in some way a reincarnation of Hoshijiro. Even though Tsumugi is aware that she's part Gauna, she chooses to defend Sidonia for her father and for the friends she made in the Sidonia. After surviving an attack by a swarm of Gauna, she swore that she wouldn't allow such things to happen to any of her comrades, solidifying her resolve to defeat them all.

In combat, Tsumugi has enough power to take on the might of a Mass Union Ship. Although her hands are gentle enough to handle a human, she can transform them to unveil Kabi-claws that allow her to destroy her Gauna brethren faster and more effectively than Guardian pilots. She can also manipulate her placenta to toughen her defenses and deflect powerful attacks. In times, when she's critically damaged, she has accelerated regeneration capabilities and can regrow her body in a matter of days.

Like the Guardian and Gauna, the source of her powers are based on Heigus Particles. With it, she can out-fly any Guardian and Gauna alike; she can use those same particles to create a beam weapon to blow away enemy targets. However, if a Gauna had the ingenuity to siphon her particles, she can be easily weakened.

When not in combat, she can be rather playful especially with Nagate, Izana and Yuhata, whom she spends the most time with. Due to her being about the size of a Guardian, she often interacts with people by extending her probe worm-like body through the pipes of Sidonia to have a life beyond the hangar. Her probe body can actually mimic human bodies, analyze the composition of objects, and can even probe the minds of people when they're unconscious. However, she enjoys spending her time with Nagate the most.

Skills & Abilities

Tsumugi destroying a Gauna

As a Chimera she possess numerous abilities that the Gauna possess as well, including using tendrils to attack her enemies, though against the Gauna, she mainly uses artificial Kabi claws, allowing her to cut through multiple Gauna easily, being able to destroy their true bodies as well.

She can also detect any Gauna nearby and magnify her sight greatly, making her completely aware of her surroundings, from a distance almost matching the range of the Sidonia's long range sensors. In terms of speed, she is much faster than most of the Guardians initially, being able to catch up to the Guardians even without a clasp formation.

When in probe form, she is capable of transforming herself to any shape she desires and is even able to imitate Hoshijiro's form, though she never does this again as Nagate scolded her for it.

Tsumugi mimicing Hoshijiro's appearance.


Tsumugi in her probe form

Being part Gauna, she mostly appears to be more like a humanoid Gauna than anything. She is about as big as a Guardian and looks like a woman in a gown of some sort. Though her face is mostly covered by a layer of placenta resembling a mask, it appears that under it she has teeth and eyes, with one eye being grown-over by placenta. Despite this, however, she is capable of showing facial emotions, noted by Nagate, much to her embarrassment. During the brief Sortie with Tsuruuchi, she knew of his personality and played with him. Making him think that her companionship with Nagate, could be shown to other Garde Pilots, she accepted the offer to fly with him at the end of the work shift. She definitely took him for a ride around the Construction site almost paralyzing him in G's and a stroke and to the other Garde pilots if they had noticed the shear enjoyment on putting him in his place, Tsumugi never , ever had a bigger Grin on her face, since that flight. Nagate to this day wishes he could have seen her grin.

When not in battle, she utilizes a probe of herself connected by a long tentacle of Placenta to her main body to move around Sidonia through the pipes. This version of herself has a single eye in the middle with two tentacles or more if necessary, that act as 'arms'.


Ochiai's Return & Tsumugi's Creation

Ochiai, a former premier scientist of his time and former Immortal Ship Committee member, betrayed Sidonia nearly a century ago and was responsible for the near complete destruction of the ship if it weren't for the efforts of Hiroki Saitou. Ochiai created his first experimental chimera hybrid and it was met with disastrous results as it nearly ruined Sidonia. Although detained, his genius couldn't be denied and the surviving leadership of Sidonia decided to preserve his mind in a giant storage device and destroyed his body; they would occasionally return to the great storage device in hopes to uncover more of Ochiai's secrets and uncover his scientific secrets. However, living up to his reputation of great intellect, he anticipated such an outcome could come and made a backup personality through his Blood Nematodes. It would be 100 years until he would return.

The Kunato Family was associated with Ochiai and they sealed away his laboratory for a century until Norio Kunato decided to investigate; Norio unsealed the forgotten laboratory. Unfortunately, this would be Norio's undoing as his body was quickly neutralized by a mere doll-like drone. A Blood Nematode, containing Ochiai's personality, took over Norio and took control of Kunato Developments. He would quietly consolidate his resources to make big changes to Sidonia.

At the time, Nagate managed to capture a placental clone of Hoshijiro. Sidonia's scientists put the Gauna specimen in observation, but Ochiai managed to convince his unsuspecting former friend and commander of Sidonia, Kobayashi, to allow him to test and experiment on Placental Hoshijiro. Utilizing his past experience, he impregnated the clone with human DNA and it didn't take long for it to give birth to Tsumugi. However, Tsumugi remained incomplete.

Tsumugi wasn't physically conditioned for combat yet, but he made enough of her to prove to Yure Shinatose of his success in perfecting the process where Ochiai failed in the past. Yure later reached out to Kobayashi, to gain approval to complete his experiments. With Sidonia desperate for a weapon(s) capable of turning the tide of the conflict, the chimera experiment was approved and Ochiai would bring himself greater power, influence, and scientific data.

First Sortie & Public Debut

Life with Nagate & War with Gauna

A Date with Nagate & Love Confession

Before the major operation to take out a mass union ship that's within LEM-VII, Nagate asked Tsumugi to spend the whole day with him. Never once able to venture within the confines of Sidonia with her actual body, Nagate got permission for the two to fly within Sidonia; he intends to tour the insides of Sidonia with his Tsugumori Custom 2 unit with Tsumugi. Nervous and excited, Tsumugi was able to have a up-close and personal view of Sidonia's residential area and experienced going to the beach for the first time. It was while at the beach that Nagate made his declaration of love for Tsumugi.

Nagate told Tsumugi that he hopes to have more experiences with her and it tearfully touched her. Surprised she would start to cry, Tsumugi admitted she always wanted to be seen by him as a normal-sized girl. However, Nagate didn't mind she's not human and the 15 meter difference in their 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 Nagate's confession, Tsumugi fainted in high heat into artificial sea. So overwhelmed that her contact with the sea actually evaporated some of the water and the steam burning Nagate. They sealed their relationship with Nagate kissing her and the two spent their remaining time floating in a blissful nap together. Unfortunately, Ochiai inconveniently disrupted their time as he finally reveals himself back to Sidonia.

Kanata's Escape & Ochiai's 2nd Insurrection

Kanata is Tsumugi's younger chimera brother. However, his existence up until now was kept secret and known to only a few within Sidonia. Ochiai, within Norio's body, utilized his experience in creating Tsumugi to create Kanata, but the chimera proved to be a challenge and nearly caused a major incident earlier; he was deemed uncontrollable and too dangerous. Kanata's higher functions were stopped with a control stake and Sidonia command had planned for his 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 his opportunity to escape instead. Although Ochiai enjoyed taking advantage of Norio's body and utilizing Kunato Developments, he felt it was time to depart as he has everything he needs to survive on his own. Having planned his departure ahead of Sidona's security, he had the enslaved Mozuku Kunato help him escape by sabotaging Tsugumori Custom 2 and killing whoever was in their way for his escape. Just as Sidonia Command was about to dismantle Kanata, Ochiai made his daring re-appearance and escaped with Kanata, not once including nor informing Tsumugi of his situation. Both Nagate and Tsumugi now launch to prevent Ochiai's calamity.

The Battle for Lem-VII

An operation was started by Captain Kobayashi to attack the large Mass Union ship orbiting Lem-VII with the use of three fleets of Mizuki-type ships with two of them carrying experimental gravitational beam emitters. Izana is placed in the recon fleet, Yuhata in the first assault fleet, Nagate remains behind until his 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 Gravitational beam emitter. however, during the battle, a huge Higgs Particle beam, that was fired from the mass union ship, hit the emitter, causing an explosion that takes out the whole fleet, the mass union ship and everyone in it. It is hinted that there were no survivors, and the end of chapter 68 shows all that is left of Tsumugi was her mangled up tail. However, in chapter 72 it is revealed that Tsumugi is alive along with one ship from the second assault fleet, though in a critical state. After arrival in his new type 20 Nagate resolves to fly her himself to the first assault fleet where she can be submerged in a vat for more intensive healing.

Saving Nagate & Death

After Nagate left her with the first assault fleet to recover, he raced towards the Lem Star to face Ochiai and reclaim the converter. The battle would be difficult due to the fact Ochiai intentionally held a controlled distance near the Lem Star, making it difficult for anyone to reach him as not many could resist the intensity of the heat. Ochiai also covered Kanata entirely of Megastructure, making his position nearly impossible for anyone to enter besides the Yukimori.

Nagate gave chase through the inferno of the star, Kanata attacked and exposed parts of itself that Nagate can effectively damaged Kanata through its armored plating. Although not defeated, Ochiai is not exposed to the elements of the sun and couldn't heal Kanata fast enough to make a difference in combat. Egotistically defiant to the end, Ochiai still believed he's critical to humanity's survival, even at the price of Sidonia. Nagate finished off Ochiai by destroying Kanata, vaporizing what's left of the chimera and taking Ochiai with it.

Although victorious, Negate's victory was only temporary. Yukimori's environmental control systems was compromised during the battle; the unit is unable to properly seal away the intense heat and Nagate is being roasted alive inside his cockpit. Because Nagate is an immortal, he was able to tolerate the extreme temperatures to a degree, but his skin was already experiencing boils from the extreme heat. He recovered the converter and attempted to fly through the harshest layer of heat, but even he knew there was a possibility he won't survive. Nagate placed Yukimori on autopilot, because he knew although his body may not make 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 this would mean Nagate's death, everyone had hoped he could survive through this like he always did in the past. Nagate would survive, but at the price of Tsumugi.

While healing inside the tank, Tsumugi was aware of the situation and decided to save the man she loved. She only partially recovered from her battle and wasn't physically fit to sortie, but she defied commands and blew a hole through the ship to escape and immediately rushed to Nagate's aid. Using her own body, Tsumugi covered herself throughout Yukimori, giving the unit a chance to cool down. Nagate was highly against Tsumugi's actions and tried to convince her to turn back, but she stayed with him as the star slowly vaporized her. In her final moments, Nagate held onto Tsumugi as she said her last words; "Tanikaze, I was happy to be born into this world. Thank you." Tsumugi was completely vaporized to Nagate's horror, but Sidonia still took priority. He made it back to the assault fleet and delivered the converter to fire the gravitational beam and took out the mass union ship at Lem-VII; Sidonia won, but at a terrible price.

Miraculous Return

It was originally thought that Tsumugi died attempting to save Nagate from the Lem Star, however, a barely-alive worm fragment of her survived within the inner gap of Yukimori's armor. Yure Shinatose at the time managed to reverse engineer the personality transfer technique from the deceased Ochiai and decided to fuse the Benisuzume Hoshijiro with what's left of Tsumugi. The process worked and it successfully brought Tsumugi and Hoshijiro back to Nagate.

The Benisuzume Hoshijiro still retained memories and experiences of the original Hoshijiro. However, after transferring Tsumugi's personality and memories into the same body, it created a new person, making Tsumugi and Hoshijiro into a single entity. Although still technically part Gauna, Tsumugi's new body is more human than Gauna; she can never regain her former body for anti-Gauna combat.

Although she had just recently gotten her new body, Tsumugi was eager to see Nagate. Still new and adapting to her human body, she managed her way to the rooftop to where Nagate was still overwhelmed with grief over her "passing." She tripped right into Nagate and she identified herself and the two were happily reunited.

10 Years Later & Bidding Sidonia Farewell

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.

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.

That day marked the time 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 across the stars. 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.


Nagate Tanikaze

Tsumugi and Nagate first Kiss

Despite never having met prior to her debut, Tsumugi expresses a lot of concern and care for Nagate after meeting him for the first time and seeing him injured, even recognizing him. Among all the pilots, she appears to be very attached to Nagate, him being one of her earliest friends along with Izana. Throughout the series it is shown that they grew closer, even developing somewhat of a crush on him, appearing to be jealous when Nagate is alone with Izana. She expresses deep care for him even when he is feeling down, even once turning her probe form into Hoshijiro to help cheer him up, though he only scolded her for this, this didn't put a dent in their relationship. Among all the pilots, she works best with Nagate, being able to destroy Gauna effectively with him as a Team, to the point that some of the other pilots are just amazed by their ability to work together. later, Nagate invites her on a date and gets special clearance to allow her into the residential area. At the end of the date while at the sea, Nagate confesses his love for her and how he wants to spend the rest of his life with her, to which she faints with shock. From the moment which have a romantic relationship, both became emotionally attached, so that when they were away from each other, were impatient and eager to revise. They also seemed to sense when one was in a life-threatening situation. In the end, as did Hoshijiro, Tsumugi was also willing to sacrifice her life for Nagate, and in her final moments, she thanked him for everything he did for her.
Izana Shinatose
Like Nagate, Tsumugi cares greatly for Izana, they immediately became the best of friends after meeting each other personally in her probe form. She enjoys hanging out with Izana, and in particular her pet cat of which she enjoys playing with. When Izana was ambushed in a recon mission, she became frustrated and agitated when she wasn't allowed to go help, though this was remedied after some convincing from Kunato to Sasaki to allow her to go help, lest she'd lose control. Despite getting jealous when seeing her alone with Nagate, she still cares greatly for her.
Yuhata Midorikawa
Though initially, Yuhata wasn't too keen on her living with Nagate and Izana, she eventually allowed it and soon they became close friends. Though there are times when they are a little on edge, like when Tsumugi tried to surprise Yuhata which made Yuhata break a leg of a model Guardian she was working on, they are still rather close. They are usually seen together in disgust or jealousy whenever Izana or Nagate spend some time alone together, going so far to spy on their 'date' from afar and making a point that their lies are easy to see through together.
Norio Kunato (possessed by Ochiai)
It is shown, that Tsumugi is rather close towards her 'father', obeying him obediently and carrying out his wishes. Though it is unclear, whether she knows of Kunato's true identity, she seems to care for him. This is most likely only one-sided however, as Kunato appears to only care about using her to fulfill his own goals, and seemingly allows her to do what she wishes to avoid upsetting her, which would destroy any chance of him reaching his goals.

Image Gallery

Notes & Trivia

  • On the cover of Chapter 63, Nagate appears holding the hand of a girl given her clothes this Tsumugi be implicit in human form.

Articles & 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 movie | Season 2 | The Star Where Love is Spun (movie) | Season 3
Subjects & Topics Sidonia | Gauna | Gardes | Technology of Sidonia | Characters of Sidonia |
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