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. Based on the manga Mamonogatari itoshi no beti.