Kyou Nukui is an introverted high school student who spends most of his time composing and publishing music online. He receives a request from one of his admirers to meet, but he's taken aback when the person turns out to be a ten-year-old girl named Jun. Now, Kyou has been entrusted with assisting Jun and her sisters in their aspiration to form their own band.
During middle school, Kyou suffered from bullying after a classmate found his personal writing. Kyou refused to return to school afterward.