Sakuma Ryuuta, a man who was overworked as a corporate slave and died from overwork, is reincarnated in another world at a magic girls' school. There, there is a class called "Sexual Intercourse Practice" that teaches female students the wonders of sex!! As the only male at the school, Ryuuta is given the role of teaching the cute and innocent female students the wonders of sex as their "harem servant"...!?