After visiting a grave several years later, Yusuke met up again and, on the way back, got off at a station with his cousin's older sister. They decided to tour the hometown town they had lived in together as children with their aunt, Yayoi. Yayoi, who had recently reunited, had transformed into a mature woman with a voluptuous figure, quite different from the past. Yusuke, who remained a virgin even after becoming a working adult and had no immunity to women, couldn't help but get excited and entertain improper thoughts. Then, as they finished sightseeing the town and were about to head back, a sudden rain started, which led to the suspension of train services, forcing them to spend a night at a hotel together.
