Zasshono Academy is a really massive non-public college with a complete of 54,000 college students from elementary stage, to junior excessive and highschool. Among the many massive variety of membership actions on the college, one membership is sort of distinctive: The Eiken Membership. The actions of this membership are shrouded in thriller, and unusually sufficient all of the members are excessively busty, headstrong feminine college students, like Shinonome Chiharu, the highest scorer within the entrance examination.

The newly arrived highschool boy, Mifune Densuke, is pressured to hitch the Eiken Membership, and instantly, his boring life up to now turns up-side down, with intense ardour, romance and far hassle!