Once upon a time, mysterious creatures called the Kijuzi invaded the solar system, causing humans to be displaced and wandering in the vast universe on a giant planet-sized spaceship Sidonia. After a long thousand years, the residents of Sidonia have not encountered Kijuzi for a hundred years, but they have never let down their guard and have trained generations of pilots who can operate humanoid weapons "Guardians". One day, a young man living underground, Tani Kaze Nagamichi (voiced by Ryota Oosaka), was forced to crawl to the surface due to hunger. He was caught after stealing rice. Later, under the instruction of the captain (voiced by Sayaka Ohara), he became a trainee of the 628th Guardian pilot. Here he met the kind girl Hoshiro Kan (voiced by Aya Suzaki) who had met him once, the friendly third-sex person Kohuse Izana (voiced by Aoi Toyosaki), and the arrogant and stubborn Norifugi Kigami (voiced by Takahiro Sakurai). Soon, the boys went out to perform a collection mission, and even encountered Kijuzi who had not been seen for a hundred years. The silent cosmic war has begun again... This film is adapted from the original comic work by Tsutomu Nibin.