The Academy Uchihama increase in the number of students is observed in recent years, in connection with which the new school building was built. The story begins during the last festival in the old school building. All the leaders of the club decided to do everything to make this festival was the best in school history. Sow a member of the infamous club of astronomy, which basically resolves various questions, instead of the studio. Council.
One day, he remains until late at night in the school infirmary as slightly injured in the classroom in a judo club.
Suddenly it shook the building. Shaken, he runs up the stairs, where, as it seems to be the epicenter, and there he meets a mysterious naked girl, which at first sight recognize him.
The next day the girl, Yui appears in the astronomy club, expressing their desire to join.