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...!?​

When Ukyo (Yutaka Mizutani) was appointed to summarize the 150-year history of the Metropolitan Police Department, House of Representatives member Ashiya (Shiro Namiki) was killed.Ukyo and Kaoru (Terawaki Yasufumi), who rushed to the scene quickly, watched the search operation of the first section.

On the other hand, this incident also caused a chain reaction in the political arena.For Tonegawa (Ogata Yoshihiro), known as the “Shadow Prime Minister”, this is the perfect opportunity to abandon Prime Minister Fujiwara (Shiba Toshio) whose support rate is low.When the head of the internal affairs investigation department, Kamiko Kamiko (Yukie Nakama), got the news, Fujiwara was forced into a corner and could not hide his shock.

Ukyo and Kaoru met unexpected characters while pursuing clues at the scene.He is the young man Takada Hajime (Kato Kiyoshiro) who once met Ukyo through other incidents and received Ukyo's help to move towards a new life. Takada Hajime is currently working as a police officer in the local affairs department. He noticed a suspicious person nearby and began to follow him.investigation.

After receiving the clues provided by Takada, Ukyo and Kaoru split up and continued to track the incident.During this investigation, Takada had a good relationship with his senior Nishina (Kenta Uchino), who was also on the same duty, and gradually showed the style of a police officer.However, events began to develop strangely afterwards.About 150 years ago, Minister of the Interior Okubo Toshimichi was assassinated. The historical cases of that year and the current emergency situation are actually highly restored...!

Behind the murder of the congressman is the ambition and conspiracy of the powerful!?