In Japanese, a “shinobi” (忍び) is a term referring to a “ninja”. Ninjas continue to dominate contemporary imagination in films, movies, comic books and cartoons. The popular anime Naruto (ナルト—) is a story revolving around several ninjas, and even in the U.S., there was a movie called Ninja Assassin in 2009.

In Japanese popular culture, ninjas exist in kabuki plays and novels such as Jiraiya Goketsu Monogatari (児雷也豪傑物語) or the “Tale of Gallant Jiraiya”. However, it’s difficult to say whether ninjas actually existed in real life. Ninjas were supposedly involved in covert activities, and the nature of their secretive work makes it difficult to ascertain the exact nature of the work ninjas did.

The Kōga (甲) and Iga (伊) clans were the only two clans that historians generally believe to have trained professional ninjas. Other than these two clans, it’s not easy to define who was a ninja and who wasn’t. Some hired mercenaries (like the drawing on the left) would perform activities of espionage for powerful feudal lords, but that doesn’t mean that these mercenaries were ninjas.

To be a ninja, one had to follow the art of ninjutsu (忍術) or the way of the ninja. Ninjutsu included sneak and attack strategies, martial arts training and other unconventional tactics of warfare (like in the drawing on the left). So did professional ninjas exist? Yes. However, they may not have been as prevalent as the Japanese folk stories have you believe.

Perhaps it’s because of the mysterious nature of the ninja that modern culture is still inspired by the ninja. In fact, the tradition of the ninja is being kept alive by the practice of ninjutsu, which some people prefer over other martial art forms.

http://www.youtube.com/watch?v=aDj2Pei-GYA&feature=related