At first glance, Fukuoka seems to be a peaceful city, however, the underside is rampant with crime. Now, and in the highly competitive business world of hit men, there is an urban legend that a hit man who specializes in killing other hit men exists. Munekata, Reiko, Shinohara, and Iwanofu are four hit men hired by the mayor of Fukuoka, to eliminate all of these, according to the city, devil humans and protect his position. Lin, a hit man hired by the Kakyuukai, commits crimes in order to pay back his debt and return home to his family. Newbie Saitoh has just been contracted as a hitman from the Killer Contract Company. He finally is given a job, but failed miserably. Senji runs a detective agency gathering information and works for the detective Shigematsu as requested to expose the evil deeds of the mayor. Avenger Jiro undertakes requests for revenge and at the same time, carries out revenge alongside requests. Lurking behind the scenes of the mayoral election is a political opposition and dark conspiracy crawling around. And when there is too much evil, the hitman killer will appear.

Zenji Banba

Voice Actor: Daisuke Ono

Zenji is a detective that runs Banba Detective Agency in Hakata. He was born and raised in Hakata making him a virile son of Kyushu. Zenji loves pork ramen, mentaiko (walleye pollack roe), and baseball. He is always stooped over.

Lin Xianming

Voice Actor: Yuuki Kaji

Lin is a hitman contracted by the rising mafia Kakyuukai, and he has undergone training in how to be a hitman since he was nine years old. When he is working, he crossdresses. His specialty is swords.

Saitoh

Voice Actor: Yuusuke Kobayashi

Saitoh is a new employee at the Killer Contract Company, Murder Inc. He was demoted from the main office in Tokyo to the Hakata branch, and he has arrived in Hakata.

Enokida

Voice Actor: Kenshou Ono

An informant, he used to belong to an overseas hacking group. His characteristics are his golden-blonde hair and flashy clothing. His stronghold is a net cafe within Fukuoka City.

Jiro

Voice Actor: Daisuke Namikawa

Jiro is an avenger. Formerly a beautician, he changed professions after his lover was killed by a hitman. Unlike how he looks, he is the token effeminate character. He works together with his assistant Misaki, an elementary school student.

Misaki

Voice Actor: Aoi Yuuki

Misaki is an elementary school student and an assistant to the avenger, Jiro. Ever since a certain something happened in her past, she was taken in by Jiro. She is constantly with him.

Shunsuke Saruwatari

Voice Actor: Yuuichi Nakamura

Shunsuke is the former ace of the Killer Contract Company, Murder Inc. He is a dangerous character who is thirsty for blood. He views Banba as an enemy.