In the year 2045, after the re-militarization of Japan, conflict erupts in Korea, and Japan is destroyed in the ensuing nuclear war. A survivor uses an old computer in the "zone" to produce a documentary from photographs, interviews and newsreels, reconstucting the last 100 years of Japanese history

About 150,000 illegal entrants live in Tokyo. They are not recognised as refugees and live in poor conditions. To protect themselves, the illegals create a secret organisation. The organisation has a bank which Japanese Financial Services Agency is not involved with, a hospital that is not authorized by Japanese Ministry of Health, Labour, and Welfare and an illegals police force called "Dias Police." The only police officer in the organisation is Saki Kubozuka (Shota Matsuda). His age and nationality is unknown. Saki Kubozuka does not speak much, but he has a warm heart and strong sense of justice. He takes care of the weak and tries to maintain public order.

When Kanako, a model daughter and a brilliant student, disappears, her mother asks her ex-husband, a violent former policeman, to find her. As his investigation progresses, his idealized image of Kanako cracks: the girl hides a dark life that her father can not even imagine.