Yuuki Wakura keeps searching for his missing sister through the rifts to Mato, the alternate dimension overrun by monsters called Yomotsu Shuuki. There he serves as squad commander Kyouka Uzen's living weapon, a role that only activates when he submits to her as her willing slave. Season 2 picks up with the two working through what that bond actually means between them as new commanders from the Azuma family enter the Mato Defense Force and put fresh pressure on Kyouka's squad.