Hotaru lives in the same house with her husband, who works from home doing telework, and her father-in-law, a successful writer. As the couple struggles with infertility, her father-in-law constantly nags them, expressing his deep desire to see his grandchild. Under pressure from his father and work-related stress, the husband increasingly turns to smoking, stepping out frequently for cigarette breaks. One day, during the five minutes her husband steps out to smoke, the father-in-law takes his place, claiming it's to help conceive a child, and immediately begins a relentless series of creampie sessions with Hotaru. Driven by a serious determination to make her pregnant, he acts with intense resolve, seizing the moment to impregnate her.