Yuriko, a mother in her fifties with a beautiful and elegant face and ample breasts, has a strong sexual desire. The mother indulges in her daily masturbation routine even though her son's friend is staying over. Her son Yukio lets his friend Akira peek at her lewd behavior, and then he engages in obscene acts with his mother, showing them to Akira. Akira, who is extremely aroused by the forbidden act between mother and son, takes advantage of Yukio's absence and confesses his feelings to Yuriko. The mother's sexual desire goes wild as she allows a young cock to penetrate her ripe body and pleasure.