Detective Ukyo Sugishita confronts crime on the basis of his own convictions. He has a partner that works for him in the Special Task Unit. For the first 7 seasons, Ukyo’s first partner is Kaoru Kameyama. He is a good-natured, hot-tempered, straightforward and somewhat scattered detective. Beginning in Season 8, Takeru Kanbe replaces Kameyama. Contrary to his predecessor, Takeru is a lanky, cool, conceited and confident detective. From Season 11 to Season 13, Ukyo’s partner is a young detective Toru Kai. Toru is a son of Deputy Director-General of The National Police Agency. But he became a detective by his own effort. And starting with Season 14, Ukyo’s current partner is Wataru Kaburagi, an elite bureaucrat who came to the Metropolitan Police Department on temporary assignment. As the first partner without any career of a police officer, he will face challenging cases together with Ukyo.

Japan has a conviction rate of 99.9% for criminal cases that go to trial. A lawyer (Hiroki Hasegawa) is able to defeat those odds and obtain an acquittal for his client, even though there's conclusive evidence that says otherwise. Sometimes, due to minor things, good and evil can switch sides and good people can become bad people.

After causing a major incident, police officer Daigo Agawa takes his wife and daughter to live in the remote mountain village of Kuge. It seems the perfect place to recover from the ordeal, despite the mysterious disappearance of a previous officer posted there. One day, the body of an old woman is found on the mountain. The Goto family says she was attacked by a bear, but Daigo notices a human bite mark. It soon becomes clear that not all is as it seems in the village.