Naoko Sugiura

The story revolves around Nayu Hayama, who embarrasses herself on the first day of middle school by accidentally showing her adult panties. As two other students, Yako Jingūji and Haruka Shiraishi, hear rumors of her engaging in "enjo kōsai", or compensated dating (which often is viewed as being close to or the same as prostitution), they investigate. They soon learn that Nayu is an 'underwear monitor' who tests new underwear products, and has great insight on what underwear people should wear. Nayu hopes to help everyone get through the vital stage of their life by opening an underwear club.

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?