Kotarou Azumi and Akane Mizuno became third year students at junior high school and are classmates for the first time. These two, along with fellow classmates, Chinatsu Nishio and Takumi Hira, relate to their peers through mutual understandings and feelings. As their final year at junior high school progresses, the group overcome their challenges to mature and become aware of changes in themselves.
The great music adventure in Show by Rock!! begins after Cyan decides to play her favorite rhythm game and suddenly gets sucked in, finding herself in a world called Midi City where music reigns supreme. She learns that anyone who delivers amazing and powerful music also has the ability to control the city. However, not all music is pure. An evil plan is set in motion to engulf the whole Midi City in darkness. Is it too late for Cyan to do something?