The Misaki high school brass band doesn't show up for it's first public performance. The next day, at band practice, The Law gang shows up; Hikuma invites them to join and experience a wider world. Aoshima responds by throwing a chair through a window, refusing to join, and leading the gang out. Later, Hikuma finds out that the Principal does a form of "neighborhood watch" in the area to steer students away from delinquency. That night, while on patrol, he sees three Law members fleeing a police officer. The three split into different directions, but the policeman catches Abo. Hikuma takes off his watch armband and pretends that Abo is his son; his daughter is asked to pick the "family" members at the Koban. Hikuma advises Abo to make the best of his final high school year, which makes him think about taking up the Trombone. The next day, The Law finds an old enemy, Jinnai, working at a construction site. Jinnai had injured Aoshima, and they face off. Words are exchanged before Jinnai is called back to work; some of The Law say they are going to be a band again. The next day, Jinnai's gang shows up outside school, demanding a faceoff. Hikuma asks them to leave The Law alone, and takes several blows before the Yankees leave. That afternoon, Abo breaks into the band room and takes several instruments out of their cases, a Trombone, among them. Takamoku and Kuwata escort him to the roof for a conversation; they too, want to play music again. Aoshima tries to assert himself, but finally releases them, saying "their friendship is over." That night, Kuwata and Takamoku are taken by Jinnai's gang. Aoshima is called out, and things are about to come to blows.

It is the second week of band practice, and there's no harmony. Hikuma proposes a Band camp in the name of unity. Hikuma has noticed that Meiho high school, which has a top notch band will also be there. When Hikuma's students arrive, they see and hear the superior Meiho high school band and are intimidated. They aren't allowed to watch Meiho's band practice, and are forced to use the camp's cafeteria to practice. To ease the tension, a softball game is arranged, which reveals even more problems among the members. Igawa, the first Saxophone leader, sees a former intermediate school friend, a Meiho band member, and his alienation increases.Hikuma cousels Igawa, who continues to resent Aoshima's gang. The next day, after an exercise session and band practice, Hikuma suggests that they have a get together barbeque with Meiho. Hikuma's daughter is interning at the high school, and wonders aloud why her father is mentoring such hopeless teens; he outlines The Plan and continues to take notes on the students. Meiho never shows up, but Igawa's old intermediate school friend entraps him into "smoking." At band practice, Hikuma collapses and is taken to the nurse's station; Igawa gets to read the old man's notebook and realizes that "demotions" to second chair are part of The Plan. The Meiho bandmaster confronts Hikuma with a picture of Igawa "smoking," announces that they're leaving, and Hikuma's Principal will be notified of the "crime." Hikuma attempts to find out which Meiho student entrapped Igawa; Aoshima's gang steps up to support Igawa and Hikuma by stopping the bus. Hikuma declares to the Meiho bandmaster that they both believe in their students...no matter what. Next morning, at band practice, Igawa moves to second chair and the band comes together.Back home, student home troubles are (partially) resolved. Hikuma goes to the hospital for more tests, and his daughter leads the band. The Principal informs Hikuma's daughter that the school is withdrawing from the contest, as Hikuma prepares for tests at the hospital.