Having drifted through space for millennia, the Sidonia found itself once more under attack from Gauna for the first time in a century. Once again facing the threat of extinction, a temporary victory against the Gauna was eked out thanks to the human-Gauna hybrid Tsumugi Shiraui and ace Guardian mech pilot Nagate Tanikaze. 10 years later... The people of Sidonia enjoy a brief respite. Peaceful days pass, during which Tsumugi begins to realize her feelings for Nagate, who is now celebrated as a hero of Sidonia. However, as Captain Kobayashi has always known, as long as the Gauna remain, peace cannot last. The decision is made: a final battle, upon which rests the fate of humanity's last survivors. As the end approaches, will the crew be able to protect those they love? (Source: Polygon Pictures)