Nanami was being bullied by her underperforming students. On the day of a makeup exam, she was forced to perform oral sex on a student, suffering intense psychological distress. At that moment, Coach Hanoka from the physical education department arrived—not to help, but under the guise of student discipline, he began raping her. Forced to wear a collar and treated like a dog in front of the students, humiliated and powerless, Nanami desperately searches for a way to protect herself.