A girl called Chiaki finds a man bleeding on the street and takes him home to nurse him back to health, only to discover that he is in fact Ororon, the King of Hell. He tells her that she is a half-breed born of a union between an angel and a human, which gives her the ability to see ghosts and put their souls to rest; however, angels and humans are forbidden to breed, and the children of such unions are outlawed. Ororon also grants Chiaki one wish - she asks Ororon to always remain by her side.

Soon, the cat demon Shiro turns up and tries to eat Chiaki, as demons find angel meat paticularly tasty; Ororon kills Shiro but mercifully brings him back to life, and he ends up living with Chiaki, along with his little brother Kuro and Ororon's housekeeper, Lucy.

Not long after that, Ororon's brother Othello arrives. He wants to take Ororon back to hell and put him back on the throne, but Ororon is reluctant to rule Hell.