Itoshi no Betty Mamonogatari
Japanese title: 愛しのベティ 魔物語
Type: Movie
Source: Manga
Episodes: 1
Status: Finished Airing
Aired: Jul 19, 1986
Duration: 53 min
Rating: R+ - Mild Nudity
Producers: Big Bang
Genres: Fantasy, Romance
Demographics: Seinen

A devil-girl with the face of an angel and a heart of gold,  blond Betty falls in love with an earthbound gangster, Danpei Kimogawa, when they meet in a rainstorm. They end up living together in a Tokyo highrise apartment, though Danpei has trouble coping with his new witch and demon in-laws dropping in at inopportune moments. Betty has actually been sent to the human world on a mission to defeat the demon Lutan. While Betty continues her task, her skeletal grandmother sends nubile nymphs to tempt Danpei and see if he is suitable husband material. 

(Source: The Anime Encyclopedia)