 After the September 11, 2001 attacks on American soil, the Tokyo Metropolitan Police Department creates a secret anti-terrorist division within the Public Security Bureau in order to tackle crime, espionage and terrorism cases to preserve Japan's national security by doing black ops work to locate and apprehend spies and terrorist suspects.The unit recruits a new officer named Hina Matsuzawa, who wishes to become a full-time detective.Leading the unit is Public Security veteran officer Keiji Sumimoto as the unit is tasked a mysterious terrorist freelancer known with the codename FISH and his cell operating in Tokyo.