As well as having to fight the Gauna, Sidonia faces conflicts within, especially following the Breach, 14 years before the series. As such, onboard security personnel come armed with a small variety of weapons.
The katana is, long story short, an elegant 2.5 foot long sword with a slight curve and a two handed hilt. Security troopers and official Garde Pilots carry Katanas looking swords at their sides.
Bow & Arrows
Perhaps the simplest ranged weapon ever. Sidonian Security officers use these to snipe at targets from a short distance, away from the close combat. The arrows seem able to to puncture Trooper armor. The use of bows rather than traditional firearms might be to prevent damage to sidonia if the shot misses.
A small air-powered pistol that fires darts tipped with sedatives. Nagate Tanikaze is found to be partially immune to the drugged darts, and had to be given three times the dosage to be knocked out.
- Katanas have always been given to high ranking figures and Japanese military officers, like how sabers were given to U.S. Calvary and Marine officers.
- It is possible that Sidonia puts all its resources to manufacturing and researching Guardian and ship weaponry to combat Gauna so there not much resources left to produce firearms and bullet for human usage but a more likely explanation is that the use of firearms is restricted while inside the ship as even a simple handgun can cause decompression if a bullet punctures an outer wall.