After abandoning music following a mishap at the middle‑school regional concert band contest, euphonist Kumiko Oumae enrolls in high school seeking a new beginning. Fate places her amid students passionate about the brass ensemble, and she discovers renewed inspiration through her teammates: newcomers such as first‑time tubist Hazuki Katou, seasoned contrabassist Sapphire Kawashima, and band vice‑president euphonist Asuka Tanaka. Long‑time companions also join—Kumiko"s childhood friend who switched from horn to trombone, Shuuichi Tsukamoto, and former middle‑school partner Reina Kousaka, a trumpet player. Yet the group is plagued by disorder; although they aim for the national competition, merely qualifying for the local festival proves daunting—unless the newly appointed advisor Noboru Taki intervenes. Their rehearsals are marked by frequent disagreements, misaligned tempos, and a lack of cohesion that threatens to derail their progress. The seasoned coach, Noboru Taki, intends to impose stricter practice schedules and refine their arrangements to restore order.
