Eri couldn't believe her ears when she found out that her son was still a virgin just before his wedding. "But you've been with other girls up until now, haven't you? Are you sure you've never done it before?" If things continued like this, their smooth-sailing married life would be in jeopardy. "There's not much time left until the wedding. What should I do...?" Eri, worried about her son's future, decided to give him some experience by using her own body to give him a practical sex education from scratch.