Kenta, a rōnin student, came to stay at his uncle's house in Tokyo for summer cram school. His uncle and aunt had married the previous year and were trying to have a baby, but due to his uncle's advanced age, there might be an issue with weak sperm? They hadn't succeeded yet. Soon after Kenta arrived in Tokyo, his uncle went on a one-week business trip out of town. As soon as the uncle left, the aunt started wearing revealing clothes to tempt Kenta, and her backstep butt (※ass) thrusts, designed to appeal to those who like big butts, caused Kenta's reason to crumble…
