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.

The son of a world famous mystery writer, Jimmy Kudo, has achieved his own notoriety by assisting the local police as a student detective. He has always been able to solve the most difficult of criminal cases using his wits and power of reason.

Kenzou Tenma, a Japanese brain surgeon in Germany, finds his life in utter turmoil after getting involved with a psychopath that was once a former patient.