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.

Autumn is in the air as the Kitauji High School concert band prepares for the National Competition. The band hears troubling news that Asuka Tanaka, vice president of the club and one of the key euphonium players in the band, may quit! Asuka is beautiful and charismatic and everyone relies on her, but she also has a cool side and never reveals her true self. Kumiko doesn’t get along with Asuka initially, but her feelings change when she learns that Asuka may actually drop out. Asuka has feelings about the euphonium that she cannot tell anyone else…

In their last year of high school, two girls in the brass band club perform a song inspired by a fairy tale that parallels their friendship.

The next piece begins! Kumiko is now in her second year at Kitauji High School, and with a new year comes new problems. As if making it to Nationals wasn't hard enough, Kumiko is tasked with mentoring the concert band's troublesome first years – each with their own distinct personality and problems to solve. With Kumiko busy juggling both the concert band and her new role as senpai, how does her relationship with Shuuichi fit into the picture?

Awaiting new club leader Kumiko is the Ensemble Contest, and the school's preliminary competition to determine the representative team to participate. Kumiko tries her best to make it to the preliminaries without incident, but the concert band club is so large that there seems to be no end to the problems. And as club leader, she finds herself busy consulting on all sorts of matters. While the other members are deciding on their teams, Kumiko herself hasn't even decided which she will join...

The music isn’t over yet! “Sound! Euphonium: The Final Movie, Part 1” is coming in 2026!

The second part of Sound! Euphonium: The Final Movie.