To avoid trouble at the prestigious all-girls Seikain Academy, Kimito Kagurazaka pretends to have a fetish for men's muscles. The school has kidnapped him to serve as their "commoner sample." His job is to expose the sheltered girls to both commoners and men so they won't be shocked when they graduate. The school assumes that Kimito prefers men and threatens to castrate him if he doesn't keep up the facade. Unfortunately, eccentric individuals make Kimito's life even harder. Aika Tenkuubashi blurts out whatever comes to mind. Hakua Shiodome is a young genius. Karen Jinryou, the daughter of a samurai, is obsessed with defeating Kimito. Reiko Arisugawa, the perfect student, dreams of marrying Kimito. These four girls and Kimito form the Commoner Club. Their goal is to teach the girls about life outside the school. As Kimito gets to know the odd girls around him, he learns a lot himself.