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.

Kitauji High School Concert Band is preparing their parts for the ensemble, but some students are fooling around when they should be practicing.

Starting this year, the band holds auditions for members participating in the competition. First-year Hazuki has a chance, too. The bass section does everything they can to encourage her.

The band is hard at work preparing for the audition and the competition. Aoi has trouble with her part, to which Taki says, "when will you be better by?"

The band is abuzz with talk about who they'll be going to the upcoming festival with. There's someone Hazuki wants to go with, but that someone is already going with someone else. Meanwhile Kumiko somehow ends up going with you-know-who.

The band suspects Taki played favorites in choosing Reina in the auditions. Noticing the band's rising distrust of Taki and Reina, he makes a proposal.

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.

The 10 members of the concert band club who failed Taki's audition form "Team Monaka" to support the club members participating in the Kyoto Concert Band competition. Even as they support the performers, they continue to hone their playing, and make monaka-shaped good-luck charms to hand out to their club mates before the competition. Although they didn't play in the competition, they still had things they had to do. But on the day of the competition, the members on their way to the concert hall receive a shocking message! This is Team Monaka's hot summer story.

Having won first place at the Kyoto competition, Kumiko and the band are preparing to compete in the Kansai competition. A shadow looms over them when an old member, Nozomi Kasaki, enters the picture.

The high school Kitauji fanfare begins its intensive summer camp before the Kansai competition. Kumiko is still trying to find out more about Asuka's refusal to reinstate Nozomi and intends to respect her promise to the girl.

Nozomi finally meets Mizore. She learns, the hard way, why Asuka had been keeping her away.

Asuka invites Kumiko over for a study party. With Kumiko's sister quitting college and Asuka's band membership uncertain, Kumiko and Reina are forced to contemplate the role of music in their lives.

With Asuka back in the competition, the orchestra is just about set for the Nationals. Meanwhile, Kumiko tries to understand why Reina is upset at her.

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?