On her first day at her new school, the newly appointed teacher, Niimura, witnesses students bullying each other in the bathroom. She immediately reports the incident, but the principal denies it... Niimura, who has a passionate sense of justice and is not satisfied with the school's tendency to cover things up, decides to tackle the bullying problem in her own way. She helps the bullying students relieve their pent-up stress and semen, and uses her own anus and vagina as teaching materials to carefully teach them about the structure of the anus and the differences between the two holes. Meanwhile, the bullying student and the bullied student work together to demonstrate double-hole sex in class...