Life is cheap in Zetsubo City. So cheap is it that a mugger will think nothing of gunning down their victim, just as law enforcement would gun down a mugger as soon as a murderer. Crime runs rampant. The ongoing conflicts between the police and various gangs and criminals verges on outright warfare. Every day, platoons of armed and armored police descend to the streets to mete out what passes for justice while the average street thug returns fire and plans ever more daring acts of criminality.

Rookie Officer Katsu Nakagawa is forced to contend with the dangers of his chosen profession all while hoping for the promotion that will put him safely behind a desk. As if that were not enough, the brass have seen fit to attach him to Seven-Gamma: a cat-like engineered bio-weapon employed as a trump card of sorts when things get too dangerous.

While surviving Zetsubo city is one matter, can Officer Nakagawa survive dragging along in the blood-soaked wake of Seven-Gamma?