A husband joins a hot-spring trip arranged by his wife's parents after years of distance. It looks like a family vacation, but his father-in-law has ordered him to abstain for a month so the couple can try for a baby. His frustration is so intense that merely passing his mother-in-law after her bath makes him hard, while his wife remains absorbed in the hot springs and refuses sex. Restlessly walking the inn at night, he accidentally sees his mother-in-law bathing, setting off an all-adult mother-in-law and son-in-law role-play filled with repeated creampies that ends with her pregnant.