Okusama no Kaifukujutsu The Animation Episode 1

Shion, who did not develop magical power even after becoming an adult, was entrusted to a young couple engaged in magic research for treatment. After a certain incident, his magical power finally manifested, but he couldn't control it, so Rui, a healer, decided to take care of him again. However, in order to be able to handle magic as a full-fledged person, it was necessary to become an adult in a sexual sense. Her married woman, Rui, cannot let Shion graduate from being a virgin, so she proceeds with the preparations on the condition that she can do it, but...