Ninjas were mercenaries of feudal Japan. They were covert agents specializing in unorthodox arts of war. Ninja functions included espionage, sabotage, infiltration, and assassination. Stories have shown Ninjas to have legendary abilities such as invisibility, walking on water and control over natural elements. It is difficult to determine whether stories are true or a product of the imagination.

Ninjas purportedly wore a suit of armor. If ever they did it was usually black colored. They were also armed with a variety of tools and weaponry. Ropes and grappling hooks were common. These were usually worn on the belt together with Ninja swords.