Iga school (伊賀流)
It was located in present Iga City and Nabari City in Mie Prefecture. They went to a battlefield or the related area to engage in maneuver activities upon order, while they search for information on each region as working as peasant or peddler in their quotidian life.
The different point from Koka school which was located in the other area parted by a mountain was for Koka Ninja to dedicate their loyalty to a single lord, while Iga Ninja had no relationship with their employer other than the financial contract made with him.
Iga school was also known for its unique training method such as running through Ichi-ri (about 3.927km) without dropping a piece of paper covering half face, and it had been their tradition to grow excellent Ninja by giving such hard training since their childhood. Sometimes, Iga goshi even had dispatched Ninja to both employers who were opposed to each other upon request. For the reason, they were required a much tougher spirit than other schools' Ninja, ready for the case that they need to make a prompt judgment even for their fellow. "Nuninseibai" was the extreme of their spirit, which meant that any betrayal and escape was strictly prohibited.
In Edo period, however, the circumstances changed, and they seemed to be rather favorably accepted to quit Ninja and return to field, because it helped reducing the cost for Musoku's salary (later mention).
From Kamakura period to Muromachi period, small feudal lords gained power in each region and were opposed to each other within Iga Province. For the reason, people began to brush up technique for guerrilla warfare for self-defense. This is considered the origin of Iga Ninja.
Iga Province was geographically unsuitable for cultivation because of its clayey soil deriving from ancient Biwa Lake layer. Particularly in a shortage of water, the rice field cracked and suffered from a devastating damage. For the reason, people in Iga Province began to work as mercenary in each region away from home.
In the Sengoku period, Iga Province formed a self-governing community with a strong council system called "iga sokoku ikki" while being affiliated to Niki clan, the Iga Shugo. In case of Iga, however, the forcefulness of speech by powerful Jonin Miyake (Hattori clan, Momochi clan, and Fujibayashi clan) was so strong that people followed their opinion most of the time when a reunion took place. On the other hand, Koka formed a self-governing community called "So" in which people had an equal position and respected the principle of decision by majority, so it was contrast to the administration of "iga sokoku ikki." In general, there might be an image that Iga and Koka were old enemies just like oil and water, but it is a misunderstanding. They rather thought that it would be nothing profitable even if they were opposed to each other in here and there parted by a mountain like neighbors, and that people in Iga and those in Koka should always be in cooperative relationship, and they made a commitment to repel the enemy if the territory which belonged to one of them was invaded.
Tensho Iga War
In 1579, Kai SHIMOYAMA, one of Iga Ninja, betrayed his fellows and informed Nobuo ODA, the second son of Nobunaga ODA, of Iga's united power's declining and proposed an invasion. Nobuo who was in on Shimoyama's words immediately repaired Maruyama-jo Castle (Iga Province) located on the border and decided to make it a foothold. But Nobuo's plot reached Iga people's ears so soon, and Nobuo was driven into a huge defeat by released Ninja's surprise attack. This is Iga War I.
Nobunaga who was furious at this outcome raged at Nobuo who had moved army without permission and admonished him suggesting breakup of their relationship, but after two years, in 1581, he invaded into Iga Province himself leading about 40,000 soldiers. This is called Tensho Iga War II. Surprised, people in Iga Province immediately decided to raise their army and fight with Nobunaga. However, Mitsuo TARAO, one of Koka Ninja who were supposed to be in cooperative relationship with Iga, withdrew another two dividers from Iga Ninja in order to put them in service as guide for Ujisato GAMO on Oda side. For the reason, the castles where Iga people barricaded themselves were successively conquered, and the fall of Kashiwabara-jo Castle which remained to the end put an end to Tensho Iga War.
After the war
At the time of opening of Kashiwabara-jo Castle, Oda army and Iga force made a compromise to secure Iga people's lives (many fictional books described that thousands of people were killed by thorough oppression and Ninja who could escape from investigation dispersed all over the country).
One of the famous episodes is that Ieyasu TOKUGAWA who had been in Sakai City rushed back to Mikawa Province guarded by Masanari HATTORI and others after Honnoji Incident. This is called Igagoe (literally, going over Iga).
When the land of Koka went under control of Hideyoshi TOYOTOMI by way of Nobunaga, Koka Ninja began to be ordered a monitoring activity on Ieyasu as main mission. In the consequence, Iga Ninja were assigned the mission to hunt down and kill Koka Ninja. This thing became a subject matter for kodan storytelling or Yomihon (a reader) in form of "Iga Ninja versus Koka Ninja" in Edo period. But in fact it was nothing but an alternative war between Tokugawa and Toyotomi.
In Edo period, the achievement of "Igagoe" mentioned above was appreciated, and they were employed by Edo bakufu as Igagumi doshin (a police constable) under Masanari who is generally known as Hanzo Hattori. For this reason, Masanari is sometimes told as if he was Ninja himself, but Masanari rather seemed to be a warrior who showed a great performance in general battlefields. For the details, refer to the article on Masanari HATTORI.
After the Todo family governed Iga, they were secured their warrior class called musoku, supplied Fuchimai (salary rice), and incorporated into the governing class.
For the reason, Iga Ninja were dispatched to a lot of uprising in all over the country for suppression including the putting down war of Amakusa Rebellion and showed a great performance. (Reference; "The Record on Ninja Village, Research on Hometown 10" 〔written by Masatomo ISHIKAWA, published by Suiyo-sya〕)
According to the record on Nakaze-mura Village (present Iga City) (Mie Prefecture) in the New Year's Holidays in 1803, the peasants' side demanded Ninja in social status of musoku to be charged boyaku as well as peasants, but Ninja's side refused it on the pretext of their being in warrior class, which led to their social ostracism.
Ninja's side appealed to a village officer for their discontent, but the village officer's side is said to have told them that they would be served as mediator only if Ninja's side returns to field renouncing their social status of samurai class or accepts to be served as boyaku.
Famous Iga Ninja