Ueda, who went to stay at a friend's house, fell in love with the beauty of his friend's mother, Ichihana, and eventually became more eager to meet than for fun. On such a night, Ueda happens to witness Ichihana masturbating while calling her cheating partner. Ichihana, who exposed her ugliness, begs to keep it secret, but Ueda, who can not suppress the urge to see that unpleasant appearance, imposes a certain condition on Ichihana, saying that she does not want to have an affair. .. And a few days later ...