Mariko is a forensic scientist working at the Kyoto PD Crime Lab. Her credo is “science never lies” and she delves into the truth of the case with her colleagues with their specialized skills and knowledge in forensic medicine, physics, chemistry etc. Mariko’s steadfast belief in science makes her stand against conventional institutional ethics of the police department, diehard detectives averse to scientific investigation and sometimes even with her own colleagues, but she stays faithful to her belief in science and continues to pursue the truth.

Suda Tamio is an ordinary salaryman. He experiences various stress throughout his daily life. His only pleasure is to set out on trips to find "Zetsumeshi." Zetsumeshi refers to endangered meals, that may no longer exist in the future. While his wife Kanae and child go attend concerts by their favourite idol groups, he leaves home on Friday after work and returns home Saturday night.

Satoshi Itomura is an assistant police investigator who belongs to the Metropolitan Police Department’s Scientific Investigation Team. Reenactments, fingerprint and voice data collections, profiling... His team collects scientific evidence and pieces together fragments of information in order to help build evidences. However, Itomura often does not care about the scientific approach and instead pays a great deal of attention to the things that the victims always carried with them or treasured. And he focuses on these things because they usually carry the victim’s dying wishes, understanding that last message not only helps solve the cases but also brings closure to the depressed family of victims.

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.

Takeshi Hongo is a promising young man with a passion for motorcycle racing. However, his dreams are suddenly ruined when he gets kidnapped by Shocker, the evil secret organization planning to dominate the world. After being remodeled into a cyborg, Takeshi escapes and swears to protect the world from the inhuman monsters.

The main character of the manga was Ishida Kotori, also known as "QP", the most powerful gangster in his area. The drama will shift its focus onto Azuma Ryo, Kotori's close friend, who has some hidden ambitions.