In the gritty, futuristic city of NeoSaitama, the streets run slick with acid rain and blood while an army of cyberneticsclad ninjas run amok under the menacing rule of the Soukai Syndicate. As incessant strife wrought by a ninja turf war takes the lives of all citizens who end up in the crossfire, one can only hope to end the day without getting a suriken to the skull. But in these dark, tragic times, a spirit of vengeance rises to kill all wicked ninja who terrorize NeoSaitama. This crimson avenger is Ninja Slayer, and he will not rest until all ninja have been slaughtered at his hands.