Seita is a musician living in Tokyo who is facing a severe creative block. He disappears, and his sister, Azumi, a young deaf girl, finds him in the mountain house where they spent their childhood. Isolated, he tries to get back to composing and begins recording birdsong for inspiration. The two brothers start living together there. Azumi’s presence, movements and sounds, which initially irritate Seita, help to unlock the boy’s creativity over time. However, the artist becomes bothered again when Taichi, Azumi’s boyfriend, decides to pay a visit.