From DrCoke at MangaHelpers:

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?