After swearing off music due to an incident at the middle school regional brass band competition, euphonist Kumiko Oumae enters high school, hoping for a fresh start. As fate would have it, she ends up surrounded by people with an interest in the brass band. Kumiko finds the motivation she needs to make music once more with the help of her bandmates, some old friends, some new. However, in the band itself, chaos reigns supreme. Despite their intention to qualify for the national band competition, as they currently are, just competing in the local festival will be a challenge—unless new band advisor Noboru Taki does something about it.