Elyse is a Lesser Devil to assist the Queen of Terror in destroying the human race. When an angel seals the Queen of Terror in Kohta’s right ball, her mission is to now to make Kohta ejaculate to free the queen, but she fails, because Kohta's erect penis disgusts and scares her...and it doesn't exactly help that she harbors a love interest underneath her layers of hatred towards him.
She has stated that she cannot return to hell until the Queen of Terror is released. While she has magic abilities, her spells have always had unexpected consequences. After she loses virginity to Satou, she realizes that she has turned human, and that her magic isn't there anymore, she starts dating Satou.