Hakata Tonkotsu Ramens

Saito is a rookie at a contract killing company, has been demoted to a post in Hakata, a highly competitive market for hitmen. Banba, a private investigator, is asked to look into a detective's apparent suicide. The detective has left behind a photo of the current mayor of Hakata, the subject of many a dark rumor. Meanwhile, Hayashi, a cross-dressing hitman in the employ of a criminal organization, is in Zhang's face demanding more money. His employer shows him a business card as a potential target, but...

Hayashi had seemingly snuck into Banba's office to kill him, but Hayashi intends to protect Banba from hitmen in order to get back at his employer, Zhang. Meanwhile, Saito narrowly avoids being tortured and killed due to a case of mistaken identity by Jirou and Misaki. Celebrating his good fortune with a night of revelry out in town, Saito awakens from a drunken stupor in a hotel room to find the body of a woman he's never seen before lying next to him.

Saito has been blamed for a murder he did not commit and hires Jiro to get revenge on the real murderer. Meanwhile, Lin learns that his sister who he left in his hometown was killed in Hakata and confronts the killer’s employer Zhang. Blinded by rage, Lin is taken by surprise by one of Zhang’s assassins and seriously wounded. Banba the detective arrives to help Lin and pledges to help find his sister’s killer.

Working with Enokida the information broker, Lin establishes that his sister’s killer is the Mayor’s son Yusuke. Having obtained information about the next human trafficking deal, Banba and Lin form a plan. Lin will pretend to be merchandise and attempt to reach the killer. But the enemy learned of their plan. Lin’s last ray of hope Banba is brutally killed by someone known as the killer of killers. Lin now finds himself in a difficult predicament.

The Yamagasa Festival, one of the three biggest festivals of Hakata, is in full swing. Banba, born and raised in Hakata, is taking time off work to celebrate. The ace assassin of a contract killer agency Saruwatari has developed a distaste for work he does not find challenging. He decides to quit and move Hakata where there is more competition. As soon as he arrives, Saruwatari’s partner from high school Nitta calls out to him. Nitta works as an assassination consultant and wants to utilize Saruwatari’s skills, but...

Saruwatari craves a strong opponent and someone proposes going after the best assassin in Fukuoka, the Niwaka Samurai. Immediately after, the phone rings Banba’s agency, but because he is at the Yamagasa Festival, Lin pretends to be the Niwaka Samurai and goes to kill Saruwatari. Forced to use weapons he isn’t used to fighting with, Lin quickly gets into trouble. Meanwhile, Banba has just gotten wind that Lin took a job while claiming to be the Niwaka Samurai.