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When Kamiyama Keito saw Oomiya Honden High School's (a.k.a. "Denkou") Rock Band "Kei-On" club, he was immediately struck by a sense of awe and admiration. Once he was admitted into the school, he immediately joined the club. To the despair of Keito, the club was run by two degenerate senior students who forbid any real practices. Once spring break turns around, Keito finds out that the two seniors were arrested for possession of marijuana, in turn pushing the club into the brink of termination. With the help of the only other member of the club, Tsukumo Shintaro, will Keito be able to prevent the termination of his club?
Honori joined the suspicious-fun club, the "Substitute Club", which substitutes for people and does their work for them. The members of this handy-man type club are very free-willed and loyal to their desires.
Kokome is a first-year high school student who is so petite she is often mistaken for an elementary school student. Together with Yukari, her very mature-looking best friend, she joins a manga and animation club at their school, led by Mimika, an elementary-age prodigy.