Masato Iwasaki, the student council president of Shuten Academy, is the daughter of the school’s headmaster and was raised as a man. She was trying to bring back love and freedom to the school... One day, a classmate is executed on suspicion of being a rebel. Masato disguises himself as the legendary savior Sexy Mask and fights against the school’s executioners and the school discipline committee. However, in order to capture Sexy Mask, the headmaster awakens the giant guard who has been imprisoned underground and captures Sexy Mask. As an example, he is subjected to humiliation.