A group of schoolgirls have formed a band to perform at their high school cultural festival in three days' time, but the guitarist and singer have quit. The remaining members, Kei, Kyoko, and Nozomi, decide to perform covers of Blue Hearts songs, including "Linda Linda", but need a new singer. They ask the first girl that walks by, Son, a Korean exchange student who is not fluent in Japanese, and name their band Paranmaum. The first day ends with all the girls working their hardest to learn their parts. Son practices at a karaoke parlor, and Kyoko talks to her crush, Kazuya. The next day, the girls begin practicing early at school. When they regroup after school, Kyoko arrives late and they miss their time slot. Kei calls her ex-boyfriend and arranges some practice time in a studio. They leave late at night to return to school, and continue practising through the rest of the night. By the next morning, Paranmaum are well rehearsed. As school begins, the girls go to their respective places to help out during the festival. Kei practices her guitar parts and talks to her rocker friend Takako. Son is supposed to help with the Japan-Korea culture exchange, but daydreams about the band. Kyoko sells crepes and Nozomi falls asleep on her bass guitar in a classroom. Kei and Kyoko wake up Nozomi and fetch Son. Son rebuffs a classmate's confession of love. Over dinner at Nozomi's house, the girls persuade Kyoko to talk to her crush Kazuya before the performance the next day. They end the night back at school, practicing until early morning. On the day of the performance, Paranmaum returns to the studio to practice. Exhausted, they fall asleep. Kei dreams about being celebrated and performing for the Ramones at the Budokan. At the school, the stage managers search for the band, but to no avail; to pass the time, their friends Takako and Moe perform impromptu music. Kei is woken by Kyoko's cellphone when Oe calls to ask where Kyoko is. The band rushes back to school in a taxi. Kyoko meets Kazuya while the band sets up minutes before the performance. Kyoko finally arrives and Paranmaum performs to an excited crowd.
The soundtrack was released on July 20, 2005. The original instrumental tracks were composed by James Iha of the Smashing Pumpkins. The vocal tracks include Paranmaum singing covers of the Blue Hearts songs "Linda Linda", "Boku no Migite " and "Owaranai Uta ". There are also two songs by Base Ball Bear ; they are "Sayonara Nostalgia" and "April Mirage". These two songs can be heard playing in the "crêpe shop" scenes featuring Kyoko and Oe Kazuya. Shione Yukawa and Hanako also perform a few songs on stage at the festival itself.
