Ninja / Shinobi of Kojin
Brief Ninja History
Shinobi or Ninja (忍者; literally: "one who moves in secrecy") were assassins, trained in the Japanese art of ninjutsu (roughly translated as 'the art of stealth'). Ninja, like samurai, followed their own special code of conduct, called ninpo. According to some modern practitioners of ninjutsu, the ninja's specialty was not assassination but rather espionage.
It is popularly believed that the ancient ninja were peasants, who were forbidden under law from studying the samurai swordplay techniques because of the caste structure of their society. This was not necessarily true as most ninja were also samurai, operating as spies in an underground intelligence network.
However, the beginning of ninja is shrouded in a secret, not least because ninja rarely left anything in writing or boasted of their achievements. Minamoto no Yoshitsune who employed surprise as a major weapon in his victories, is said in a popular folktale to have been educated by a Tengu to learn the tactic and became a ninja. In truth, he was educated by Buddhist monks who educated him with Chinese books like The Art of War.
In the Nara period, shugendo, a style of Buddhism that focused on training one's body to achieve enlightenment, satori, became recognized and publicily accepted. Some of the trainees made a secluded village deep in a mountain to support themselves and some of these villagers would later evolve into Shinobi no Sato, literally "village of shinobi," when confusions of feudal period raised the need for a defense against local warlords. Mikkyo, introduced in the early Heian period, further enhanced the secretive nature of these villages and added mysterious aura by their indulgence in secret ceremonies. One of the earliest roots of ninja, Togakure-ryu, reportedly originated in the late Heian era. Iga and Koga are two of the most famous ninja styles, and are often pitted against each other in fiction. Both of these claim that they originate in Heian period.
Only a few records remain from the Kamakura period. Kusunoki Masashige used some clever tactics against enemies that remotely resemble some of ninja tactics. From the Muromachi period there are even fewer records. Both of these times were generally peaceful, and many battles had tournament-like aspects that barred a surprise attack. Somewhere in these time periods, bushido begun to form as the proper and honorable way a samurai must follow. It would be well into Edo period that bushido was finally formalized and until then ninpo was not well separated from bushido.
Continue to Ninja in the Sengoku Period.