Ninja

 The mercenary or covert agent of feudal Japan, a"ninja" (Ren Zhe, Japanese pronunciation: [nindza]), was called Shinobi (Ren Bi, also known as [cinobi]). The duties of a ninja include reconnaissance as well as espionage, infiltration ambush, deception as well as their combat skills in combat sports, such as Ninjutsu. The methods they employed to conduct irregular warfare were deemed unacceptable and in violation of the honor of the Samurai. Shinobi, who were specifically trained mercenaries or spies, first appeared in the Sengoku period in the 15th century. But, there could be some antecedents from the 12th century. In the Sengoku period, hired spies and mercenaries were active in Iga Province, and the surrounding area, around Koga. This is where the bulk of the information regarding the ninja originates. After the unification of Japan under the Tokugawa shogunate in the 17th century, the ninja faded into the shadows of. Shinobi manuals in a variety of formats that were usually inspired by Chinese military philosophy, were written in the 17th and 18th centuries. Most particularly the Bansenshukai (1676).