Kumiko enters Kitauji High School having been unable to forget what Reina said at a middle school concert band competition. She goes to visit the concert band at school along with classmates Hazuki and Sapphire, where they meet Reina again.

Kumiko and the others prepare for Sunrise Festival. Kumiko and Shuichi talk about Taki-sensei on the way home from school, when they run into Reina.

The competition performance is "only" 12 minutes long. It's both a blink of an eye and an eternity. The Concert Band members bet their entire youths on this competition. And Kitauji High School Concert Band's performance begins.

With the competition over and the third-years graduating, Kumiko is left to sort through her feelings: Is it a love of concert band, of the euphonium, or of something else?