Hisaki and Yasha are an odd pair of friends: Hisaki is quiet, distant, and possibly keeping secrets from everyone, while Yasha is loud, violent, and in serious need of anger management. As they try to deal with each other, they soon find that creatures are after them for something they know nothing about: a demon supposedly hiding within one of them.
Yasha is trapped in her prison cell with no real hopes for escape. The only person she has contact with is the loyal soldier, Sato...but he seems conflicted about turning over a human girl to Akujin. Will he be the key to escaping?