Jun Fudo models for a living, unaware that the genes for humanity's next mutation are already in her. The beast-like superhumans tearing through the city carry the same blood, and Jun is the one who can change into one and come back as herself. Asuka Ran, an agent of a secret government body created to contain those creatures, recruits her. As the Devil Lady, Jun is sent to exterminate her own kind, in a situation she never chose and cannot refuse.