Shion is a plain girl with black hair who doesn't stand out much in class. But if you look closely, you can see that she has slanted cat eyes and a lewd gaze. She makes some extra money by having sex with men without telling anyone, not even her parents or classmates. There's only one reason for that - she has an extraordinary interest in sex. Shion hides her sexual desire like a cat, and her school life, or rather, her school sex life, is fully recorded here.