Ken, who thought he would never have a relationship with a woman, suddenly finds himself living a rosy life. His mother's best friend, Satsuki, comes to stay the night. Ken didn't have high expectations of his mother's best friend, who is just an old lady, but Satsuki's adult sex appeal makes his heart pound. Unable to suppress his arousal, Ken waits until Satsuki is taking a bath to try to use her freshly removed underwear as a masturbation aid... but unfortunately, he runs into her.