Momoko, a mother, feels a little lonely lately as her son Tetsuya is going through a rebellious phase. However, she is comforted by the friendliness of her son's friend Shinji, who comes over frequently. One day, while Shinji is helping her with her daily training, Momoko becomes aroused by his strong body... Momoko makes a move on him without much thought, but Shinji, who can't forget the pleasure he once experienced, has been seeking her like a monkey over and over again ever since. Momoko's body screams in pain as Shinji's tough sex...