“Koichi, when are you finally going to give me a grandchild?” My mother-in-law's question catches me completely off guard. What was supposed to be a fun family hot-spring trip turns into pressure to try for a baby with my wife. After abstaining for a month at my mother-in-law's urging, I arrive at the inn full of anticipation, only for my wife to refuse baby-making sex. Frustrated and restless, I wander around the inn and accidentally catch sight of my mother-in-law bathing. I lose all control and creampie her again and again during the overnight trip, leaving her pregnant with a secret I can never confess to my wife.