The story is about an assasin name Train Heartnet who deserts his organization Chronos, and becomes a sweeper(someone who catches wanted criminals for a reward from the government) after his partner Creed kills his best friend Saya. Train is soon joined by another sweeper Sven, a "tief for hire" named Rinslet Walker, and a girl with incredible abilities named Eve. Together, the group sets out to avenge Saya and stop Creed from dominating the world,and catch a few crims to  earn some cash. When Creed becomes to powerful to handle, they also get help from other sweepers and even Chonos......Black Cat is the Best manga ever.....Read it!