At Sachiko's comes the son of the Katō family, a long-time family friend. Though still a young boy, he takes advantage of Sachiko's carelessness, playfully groping her big tits, and when they bathe together, his cock gets fully erect at her pussy. Flustered by his actions, Sachiko reluctantly begins helping him with his sexual needs, gradually falling into sexual frustration herself. As a result, the two end up experiencing their first night together far earlier than expected.