Ataru leaves his cell phone at Shinya's house. On his way home he realizes this and rushes back to get it, only to find Shinya and his mother Tsuyuko pressed together. Ataru is so captivated by the sight that he can't take his eyes off it, and his eyes meet Tsuyuko's. In the end, he ends up running away in a panic that day, and is unable to take his cell phone home with him. The next day, when he finally decides to go and get his cell phone, Tsuyuko seduces him in sexy underwear, asking him to keep quiet about the fact that she and Shinya are in a physical relationship.