Ikuo RyuzakiThe main character and the younger of the Twin Dragons. Ryuzaki elected to join the MPD while Danno joined the Yakuza.
- Bunny-Ears Lawyer: behaves rather peculiarly but is still an extremely effective police officer
- The Cape
- Establishing Character Moment: sniffing the mouth of a corpse to determine what their last meal was.
- Screw the Rules, I'm Doing What's Right!: will often get involved in cases that the police department chooses to ignore.
Tatsuya DannoThe older of the Twin Dragons, a no nonsense member of the Yakuza and the duos eye in the criminal world.
- Big Brother Instinct: towards Ryuzaki, much to his own annoyance.
- The Cowl
- Heterosexual Life-Partners: with Ryuzaki.
- Precocious Crush: a flashback indicates that he may have had one on Yuiko-sensei.
Miduki HibinoRyuzakis long time partner in MPD
- Hollywood Homely: she looks plain at worst, even when work gets in the way of her personal hygiene.
- Missing Mom: her mother died while she was very young.
- Parental Neglect: as a child the most she saw of her father was when hed come home to change his clothes.
- Smurfette Principle: In-Universe example, one of only three women in the first division of the MPD.
- Shes also a Deconstruction as she is often looked down upon and suffers through several instances of sexual harassment from her male peers with few exeptions.
- "Well Done, Daughter!" Girl: its been established that one of the reasons she joined the police force in the first place was so her workaholic father would finally, pay attention to her.
Golden WatchAn unidentified police officer who covered up Yuiko-senseis murder.
Shinjuku Second Division
Kaoru MishimaSection Chief of the Second Divisions criminal affaires department.
- Crouching Moron, Hidden Badass: on the outside hes a jovial, laidback officer looking for someone to share a drink with, but he didnt get to be a section chief on that alone.
Naotarou KuraSecond Division detective partnered with Kandori Kazuma.
Shinjuku First Division
- Hometown Hero: a few chapters focusing on him showed him being treated this way in his neighborhood.
- Inspector Javert: something of a subversion, while he is determined to figure out the connection between Danno and Ryuzaki, he mostly treats it as a hobby and doesnt drop everything hes doing or neglect his other police duties to chase after either of them.