In order to save her younger brother from bullying at an all-boys school, Mahiro disguised herself as a boy and snuck into the school. She managed to put an end to the bullying by exploiting the weaknesses of the tormentors. However, once they discovered that she was actually a girl, they launched a vicious counterattack against her. Initially strong-willed, Mahiro gradually succumbed to the pleasure of submission and became consumed by lust, losing control and experiencing intense orgasms...

男子校に通う弟をイジメから救うために姉のまひろは男装して学校へ潜り込み、いじめっ子たちの弱みを握ってイジメを止めさせることができた。しかし、まひろが女だと知ったいじめっ子たちにまひろは逆襲の凌●を受けてしまう。初めは強気のまひろだったが徐々に被虐の快楽に堕ち、淫欲に溺れてイキ乱れるのであった・・・