, ninja and title character of the Japanese folktale Jiraiya Goketsu Monogatari.]] In the history of Japan, a was someone specially trained in a variety of unorthodox arts of war. The methods used by ninja included assassination, espionage, and a variety of martial arts. In the Japanese culture, they were usually trained for dangerous missions. Although their exact origins are still unknown, it is known that they appeared in 14th century feudal Japan, and remained active from the Kamakura to the Edo period. Their roles may have included sabotage, espionage, scouting and assassination missions as a way to destabilize and cause social chaos in enemy territory or against an opposing ruler, perhaps in the service of their feudal rulers (daimyo, shogun), or an underground ninja organization waging guerilla warfare. Etymology Ninja is the on'yomi reading of the two kanji ?? used to write shinobi-no-mo