Kobayashi — known throughout Tokyo's underworld as the Shinjuku Vampire — operates as a feared assassin for hire, armed with a mystical blade and supernatural abilities fueled by the blood of those he has already killed. He takes out the city's most dangerous and deranged targets, one job at a time. Then the Flatliners appear. Mysterious, unlike anything Tokyo has seen before, they open up a whole new dimension of insanity and depravity — one that Kobayashi is about to be pulled into headfirst.