Season: 2

Evicted from his dorm and with nowhere to go, Nagate asks to stay with Izana for a night; Tsumugi has an emotional crisis triggered by a close call.

Despite being instrumental in their victory, Tsumugi is severely damaged defending Sidonia. Izana, also critically injured, makes a bold decision.

A new threat appears in the form of Gauna 550, which has ejected countless lesser gauna cores on an intercept trajectory with Sidonia.

Having disposed of the opposition, Kobayashi sets Sidonia's course to the ninth planet in the nearby Lem System. All-out war now seems unavoidable.