When his mother-in-law asks when she will get to see a grandchild, Kenta is stunned to find their family hot-spring trip has become an opportunity for her to pressure him into trying for a baby with his wife. He follows her advice and abstains for a month, only for his wife to refuse sex on the trip. Frustrated, he wanders the inn and accidentally sees his mother-in-law bathing. Losing control, he begins an affair with her and repeatedly creampies her, leaving him with the secret that he has gotten her pregnant.