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.
The hardened veteran detective Rena and bright-eyed rookie Sato take on a menial investigation. The job goes well until a thug named Dobu steals their evidence. Disheartened, they take a job looking into the life of a taxi driver named Odokawa in hopes of redeeming themselves. They wind up in the middle of a missing girl case, with gangsters, aspiring students, and surprises around every corner.
One year after the hospital occupation incident, Saburo Musashi (Sho Sakurai) of the Kanagawa Prefectural Police Investigation Division has another "worst day" ...! Kanagawa Prefecture's first international airport "Kanagawa New Airport" is suddenly occupied by an armed group wearing a beast mask!
