Yuki, a son, feels his heart pounding when he is reunited with his mother's friend, Ayaharu, who has come to stay the night for work. One night, while looking at his mother and Ayaharu, he passes out drunk and wakes up in the middle of the night... Unable to sleep, Ayaharu is tormented by the alcohol and accidentally witnesses her masturbating in her bedroom. Unable to contain his excitement in the awkward atmosphere, Yuki embraces her... Ayaharu accepts his forceful advances, but the next morning she acts as if nothing happened. However, Yuki cannot forget the pleasure he once experienced...