The story of Season 23 begins with Ukyo accepting instructions from his superiors to compile the 150-year history of the Metropolitan Police Department.

In the 7th year of Meiji, the Metropolitan Police Department was founded by the former Satsuma feudal lord, Kawaji Toriya.Together with the Secretary of the Interior, Toshimichi Okubo, he founded the police agency and became the first-generation police chief (currently the police chief).However, Okubo later suffered the tragedy of assassination——.Like that incident in the dawn of the police, there was an incident where a big shot politician was killed!What stands in the way of the Tomei-kei who begin the investigation is the reality of the widening gap between rich and poor in modern Japan, as well as the ambitions and conspiracies of powerful people spreading in the political world -!?

150 years ago and now——As society changes, has “Justice” also changed...!?​