It's the story of a professional Japanese killer who runs into some resistance during his latest assassination and after the ensuing shootout, ends up with a bullet in his head. He survives, but with this constant and at times quite painful reminder of the price of violence permanently lodged deep inside his brain, he changes his outlook on life. In fact, the only thing that keeps him from turning suicidal are the adrenaline rushes he gets from extreme situations. He begins to seek out danger and approaches it as if he didn't care about his life, and maybe he doesn't. While doing so, he gets involved with a group of criminals in HK, and makes friends with a young cop and former SDU sniper who can't get over the fact he accidentally shot a fellow officer.