Sixty years have passed since humanity's defeat by the Void. The survivors relocated to a new planet, Cradle, and continued to fight while training compatible individuals at Aegis Academy. you, assigned to the Field Division, has finally been given a buddy. While everyone fights with special firearms called V-As, he is the lone eccentric who wields a specially processed katana. A rough, dangerous problem child who never partners properly with anyone. - We're all just expendable goods to be used up anyway - So he says, yet he charges the front lines sharper than anyone else—Setsu Aiba. Heading to the training ground for their first meeting, amidst the sound of clashing metal, a single blade slices a Void target clean in two.