With the ensemble contest behind them, the Kitauji High School concert band members now set their sights on winning a gold medal at the national competition. For third-year club president Kumiko Oumae and her friends, this represents their final opportunity before graduation. Burdened by both anticipation and anxiety, Kumiko questions whether she can effectively lead the band. Amid her struggles, Kumiko meets transfer student Mayu Kuroe. Possessing a gentle demeanor and skilled euphonium playing, Mayu was formerly a member of the Seira Girls' School concert band, a regular competitor at nationals. Although Mayu is friendly, Kumiko finds herself experiencing an indescribable feeling following their encounter. As new members join and plans take shape, the club, driven by an insatiable hunger for a gold medal, discovers what it truly takes to elevate themselves to the national level.