Based on the erotic game by Alice Soft.

Shion, who has not developed any magical powers in adulthood, is left in the care of a young couple engaged in magical research in order to cure him. An incident finally led to the development of his magical powers, but he was unable to control them, and Rui, a healer, was once again assigned to take care of him. However, in order to be able to handle magic on his own, he needed to mature in a sexual sense. Rui, a married woman, cannot allow Shion to lose his virginity, so she makes preparations for him on the condition that he will remain a virgin until he has a girlfriend......