When he was young, Arimasa Tsuchimikado rescued an injured cat and wished for it to become human. The cat, Kagetsu, is actually a member of the shape-shifting Kouga tribe and comes to live with Arimasa.

Years later, Arimasa is an uneasy presence in his village. The villagers despise him for being half-fox, but he is also the only one able to protect the village against supernatural invasion. Meanwhile, Kagetsu is going through a difficult period where he must choose which sex he will live the rest of his life as, a process he can only complete through sexual intercourse.

As pressure from other members of the Kouga clan opposes the wishes in Kagetsu’s heart, Arimasa's village is struck by a large-scale supernatural attack. With his peaceful life threatened, Arimasa will be forced to make undesirable decisions.