Rei Ichidou, Gou Reietsu, Kiyoshi Shusse, Jin Daima, and Dai Monohoshi are five unruly lads at Ichiou Junior High. Each boasts a quirky temperament and an instinct for mayhem, earning them the notorious tag "Kimen-gumi."
One day a new transfer, Yui Kawa, and her companion Chie Uru run into the crew and quickly become entangled in their shenanigans. Nearby, a spectrum of other groups thrives: the dashing "Iro Otoko-gumi" commanded by Shou Kireide, the rebellious "Ban-gumi" led by You Nihiruda, the fit "Ude-gumi" headed by Kai Undou, and the fierce female clique "Onna-gumi" under Jako Amano.
As spring rolls in, the daily adventures of these eccentric pupils unfold into a spirited and humorous school saga within the bustling campus for the whole year.