Knights of Sidonia Season 2: Battle for Planet Nine
In a war with the alien Gauna, capable of absorbing and re-purposing human DNA, pilot Nagate Tanikaze finds himself developing an obsession with the Gauna clone of his deceased beloved, Hoshijiro. Meanwhile, his close friend, Izana, a manufactured non-binary human, goes through an alarming change as their feelings for Nagate grow. Existential and romantic problems will have to wait though, as the Guana step up their attacks and Sidonia is threatened from turmoil within.