On Christmas Eve in 2004, Takahiro Noguchi (played by Tokui Yoshimi) and his wife Naoko (played by Konishi Manami) were both killed in a high-end apartment. There were four panicked young people at the scene: Sugishita Nozomi (played by Eikura Nana), Naruse Shinji (played by Kubota Masataka), Ando Nozomi (played by Kaku Kento) and Nishizaki Masato (played by Koide Keisuke). In the end, Nishizaki pleaded guilty and was sentenced to ten years in prison. Takano Shigeru (played by Miura Tomokazu), a retired criminal policeman who once served as a police officer on a small island in the Seto Inland Sea, has many questions about the case. Nozomi and Shinji, who were born on the island, were involved in a mysterious fire. Nozomi and Ando were college classmates after going to Beijing, and the two rented the same apartment with Nishizaki. The four young people and the Noguchi couple are inextricably linked together. Everyone has an "N" that needs to be protected. They use lies to compile a confusing love-hate puzzle... This film is adapted from Kanae Minato's original work.