She is a model, who during a Demon attack is raped and turned into a powerful Demon herself. She spends her time coping with her humanity, and sexuality. She helps Lan Asuka's organization in hunting down other demons. Traveling through the nine circles of Hell she encounters Devilman (who had died at the end of the manga series). She discovers from him that the world was once destroyed and had reborn in a time/dimensional flux.
Its later revealed that she is the female half of Satan