Hakata Tonkotsu Ramens

From Endless Journey:  
An assassin from Kitakyushu appears. Hakata: a town rumored to count 3% of the population as killers. Saruwatari, a dangerous man in search of thrills, hears the rumors of a "killer of professional killers"  and comes to this battleground for professional killers. Add in Nitta, a hitman consultant, and trouble may arise in Hakata once again!

In Fukuoka, crime reaches new heights in the seedy underworld. In the Hakata ward of the city, there are various individuals with special talent who are professional killers, detectives, informants, and professional revenge seekers. Among those, a so-called "killer of professional killers" is becoming more than just an urban legend.