Based on the manga by Fuusen Club (風船クラブ)

In a dark, empty school building, Kiriko is bound and gagged, wearing only her underwear. In front of her, there are three men wearing masks. They tell her, "I want to see your body drown in pleasure, and your face contort in ecstacy." These men had much experience with other female teachers. They would continue their perverse assault until their prey cried out in ecstacy. However, Kiriko is a strong-minded, martial arts expert. Two of the men were already lying wounded in the nurse's room. As Kiriko threatens to turn the men into the police, her epithets start to excite them. They tell her that if she can stand the men playing with her pussy for ten minutes without getting wet, she can go. As they play with her body, her mind and reason dims in a wave of sexual pleasure....