Sven is your run-of-the-mill sweeper (a.k.a. bounty hunter): down on his luck, haunted by the perpetual grumbling of his stomach and looking to make enough cash just to get by. When a damsel in distress enlists his aid, Sven crosses paths with the worst possible luck: Black Cat (a.k.a. Train Heartnet). At odds now with the branded assassin, Sven seeks to save a young girl before the unlucky Number can carry out his mission.