One day, teacher Mari and her husband, Tetsugaku, a fellow teacher, visit the home of Yugo, a student in their class who refuses to come to school. The school has given up on Yugo because of his problematic behavior, but Yugo comes to make a home visit despite their protests. However, as soon as Yugo welcomes Mari, he gives Mari and Tetsugaku tea laced with sleeping pills and pins Mari down in front of Tetsugaku. In the middle of the act, Yugo's father Satoshi, a yakuza, and his thug subordinate appear and gang-rape Mari.