Yutaka came to stay overnight at a friend's house. There, he happened to see his friend's sister Aki's voluptuous naked body after a bath. He got so excited and nervous that he got a hard on... Seeing this, Aki couldn't suppress the throbbing in his body that had been building up while living away from her husband who was working away from home, and he played with his crotch with pleasure. Aki was satisfied by taking Yutaka's virginity as she pleased, but Yutaka, who had awakened to the pleasures of sex, was not satisfied with that alone...