Nabari No Ou: The Complete Series
In the shadows of this modern world, ninjas fight for control of an ancient technique which holds untold strength. This coveted power dwells within apathetic Miharu, a fact the guy really couldn't care less about - until the clashing rival clans bring their battle to him.
Now Miharu struggles to understand the mystery buried in his soul, and must choose a side if he hopes to survive. But when conflict is waged in secret, and lethal ninjas hide in plain sight, friend and foe prove difficult to tell apart.