Shion, one of the seven rulers of the underworld, harbors the ambition of being crowned as the next demon king. To succeed in the Demon King Succession Exam, he needs to acquire the heart of his chosen human target – a delicate and pure-hearted girl named Umeko Makimura. Unlike the customary practice of stealing a human soul, he must claim her virginity. In a cover-up of a new transfer student, Shion infiltrates Umeko's school. Following the romantic notions of shoujo manga, he strives to create an intimate bond with Umeko. However, Shion's attempts to win her over force him to confront his own feelings for her.
