On a fall day a month before the school fair, Haruki Kitahara's Light Music Club is about to be disbanded, thanks to trouble caused by their beautiful vocalist, Tomo Yanagihara. Haruki tries to find a new member, but despite his own problems he's forced to help with the School Fair Committee too. There he meets Setsuna Ogiso, winner of the Miss Houjou contest for two years running, who wants to withdraw from this year's contest.

The Light Music Club's members are finally together, and with the School Fair only two weeks away they begin to practice. With their schedule almost murderously tight, Kazusa proposes a plan to fix their biggest problem, Haruki's guitar playing. After a great deal of training, the three finally master their first song, White Album.

Setsuna realizes that Haruki has been staying at Kazusa's house this whole time, and she reveals her true self to him: cowardly, introverted, and pathetic. But Haruki accepts her as she is. The boundary between them is broken, and the bonds between the three grow stronger as the school fair draws near. But Kazusa is skipping sleep and food to work on her "last trick" before the school concert.

Ever since the school trip, Kazusa hasn't come to school. Haruki tells himself that it's because she's practicing for the upcoming recital, but part of him is still struggling over what's happened. And even when he's with Setsuna that doesn't go away. He finally invites Ogiso to a birthday party, with just the two of them, to finally come to terms with his feelings. But he doesn't know that Kazusa is making a big decisions of her own...

At last Haruki realives Kazuma's true feelings, but while he's confused at this sudden turn of events he can't hide his joy that the girl he loved best likes him too.

Haruki collapses after saying goodbye to Kasuza, and Setsuna, who he betrayed, comes to take care of him. Haruki is too overcome with guilt to move, and Setsuna tries to pretend she knows nothing as she struggles with guilt of her own.

At last, Haruki sleeps with Kazusa. Her wish finally comes true, and she prepares to leave for Europe. Haruki takes Setsuna to the airport, hoping that they can all be together once again. When the three are reunited, everyone remembers the best moment of their lives: the last song they sang at the school concert. The title of the song was...