A pregnant daughter contacts you urgently, so you rush to her parents' home in Tokyo. Upon arrival, she tells you about some issues going on but also mentions that her stepson, Junya, keeps pestering her. She seems to have called you over as a distraction from his advances. However, things escalate when she reveals that not only does she forbid him from masturbating, but she has even issued an explicit ban on it! Despite this, you can't help but feel sorry for him after hearing his story. One day, while trying to calm him down, you accidentally loosen his restraints. His pent-up sexual desires explode, and he aggressively thrusts his throbbing cock against his stepmother's plump body...