The Sakuragoaka Girls' Academy curriculum traditionally focuses on the three "R"s of reading, writing and arithmetic, but Ritsu Tainaka wants to add two more "R"s: Rock and Roll! To do that, however, Ritsu has to save the Light Music Club from being shut down due to little problems like not having any other members or a faculty advisor. After strong-arming her best friend Mio into joining and convincing Tsumugi Kotobuki to make it a trio, Ritsu's would-be rockers are soon only one talented guitarist short of the quartet they need for school approval. What they get, unfortunately, is Yui Hirasawa, who's never held a guitar in her life, but she's determined to learn! Will the school halls come alive with the sound of music?

Her name is Esumi Fuuka. Standing tall at 163 cm with a slender bodyline, she must be a university undergraduate; however, in reality, she is only an elementary school student. With a body figure of an adult and the mentality of a small child, she creates many misunderstandings around her.