New teacher Nao takes charge of a troubled class ruled by an adult bully-student role-play character. Her strong sense of justice drives her to defend someone being picked on, only to discover it was a trap. In the gym storage room, she is drenched in sensitivity-boosting liquid, tied up with her legs spread, and left under relentless vibrator torture. She desperately tries to stay in control, but once the liquid kicks in, she can no longer resist the pleasure...