Michiko Uchiwara turned 60 six months ago. She gave birth to her first child at the young age of 18, and that daughter gave birth to her son, Yohei, at 19. Yohei is now 23 years old. Michiko has long enjoyed secretly borrowing AVs from Yohei's room to watch, but one day he discovered her habit. Excited by the encounter, Yohei initiated a sexual relationship with her. Now, under the pretense of a hot spring trip, they secretly check into a ryokan behind their family's back, continuing their forbidden, intimate affair.