The beautiful and successful supermodel Jun Fudou meets a woman named Lan Asuka, who confronts her with a werewolf monster, which she calls a devil beast. As a result, unimagined powers awaken in Jun, and she manages to defeat the monster. She, just like this werewolf, is part of the next step in human evolution: humans who can mutate into beast-like monsters and then mercilessly terrorise civilisation. Unlike the other devil beasts, however, she can retain her humanity, which is her undoing because Lan Asuka is a high-ranking employee of the government and of the “Anti-Beast Special Squad”, which wants to abuse her powers and train her to mercilessly hunt down her own species.

Caught between these extremes and her weak self, the question arises: what fate will Jun meet? Will she ever be able to decide it for herself?