Iga Ryu & Momochi Sandayu

IGA School of Ninja

Iga School 伊賀流 is one of the most famous schools of Ninjutsu as well as Koga School 甲賀流. 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.

Characteristics of Iga School

The different point from Koga school 甲賀流 which was located in the other area parted by a mountain was for Koga 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.

History of Iga School

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 Tensho Iga 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). Afterward, Iga Ninja who were informed of the death of Nobunaga in Honnoji Incident rose in rebellion and caused conflicts in each region. 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.

Edo Period

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.

The Ninjutsu of Iga Region, Japan & Momochi Sandayu

“Ninjutsu is not something that should be used for personal desires. It is something that should be used when no other choice is available, for the sake of one’s country, for the sake of one’s lord, or to escape personal danger. If one deliberately uses it for the sake of personal desires, the techniques will indeed fail totally.”

Momochi Sandayu – Soke Iga Ryu Karate, Koto Ryu Koppojutsu, Hakuun Ryu Ninpo / Gyokko Ryu Kosshijutsu

This quote from Momochi Sandayu a famous Shinobi master who existed in the 1500s in Iga Province – Japan.

The famous Shinobi Momochi Sandayu, the head of the Momochi Clan of Shinobi, existed in the beginning of the golden age of Ninjutsu when the Shogunate style of government came about with the rise of the Samurai caste. Momochi Sandayu was born in 1525 and is known to be one of the founders of Iga ryu Ninjutsu and trained many of the most famous Shinobi of that time including Hattori Hanzo and Ishikawa Goemon. Momochi Sandayu was known by his title of nobility Tanba no Kami. He used many different disguises and aliases and his history is covered my a shroud of deception. One of his aliases is the name Fujibayashi Nagato who was the master of Koga Ryu Shinobi. Momochi was the head of many households but his main home was at Ryuguchi in Nabari City in Iga Province. Momochi was also rumoured to have had a Shinobi training facility in Hojiro in Ueno City. Sandayu managed to maintain three seperate households with a seperate wife and family living in each. By establishing himself in three different locations with three different identities he ensured his own safety and secrecy.

Momochi Sandayu was the Soke (Grandmaster/Family head) of the Koto Ryu Koppojutsu, he learnt Gyokko Ryu Kosshijutsu from Hakuunsai and he studied the Togakure Ryu Ninjutsu and passed its knowledge to the Natori family of Kishu which later became a part of Kishu Ryu Ninjutsu. His strategy in combat was to use unorthodox techniques in order to make his adversary believe he did not know what he was doing. The decree of Momochi Sandayu follows:

“The art of the Shinobi is not to be employed for personal gain”

“The art of the Shinobi is to be employed, with a deep understanding of the essence of Gyokko, for country, for lord, or in times of inescapable personal danger”

“If the art of the Shinobi is willfully employed for personal gain, the art of our forefathers will certainly be defeated”

Iga Province is a small mountain ringed basin, known as Ueno basin, in the centre of Japan’s Kansai region, on the island of Honshu. During the early Muromachi Period of Japan’s history, which covered the approximate period of 1336 – 1573, Iga Province became independent from their feudal leaders and established a form of republic. The Iga Republic was known as Iga Sokoku Ikki (伊賀惣国一揆) in Japanese.

Iga Province was said to be controlled by three ninja clans with Fujibayushi in the north, Hattori in the center, and Momochi in the south. It was in his camp at Hojiro that Momochi trained his famous Iga Shinobi and controlled the southern end of the province.

Momochi challenged the power of the Christian warlord Oda Nobunaga as he ascended to power. Momochi was using his Shinobi network to secretly steer the fate of Japanese history in order to shape its future. The Iga Shinobi allied themselves to their Buddhist brethren and worked to protect the sacred shrines and temples of Buddhism. Oda Nobunaga and his two generals, Hideyoshi Toyotomi and Ieyasu Tokugawa were known to use spies but none were from Iga and Koga. Oda Nobunaga and Hideyoshi Toyotomi were overtly opposed to Buddhism and burnt temples at every opportunity but this made them the sworn enemies of the Shinobi of both Iga and Koga.

Oda Nobunaga learnt of the success of the Iga Shinobi operations against his forces but by being so successful the Iga Shinobi had revealed themselves. There were also failed assassination attempts against Oda Nobunaga which made him determined to defeat the Iga Shinobi on their own turf. He sent his son with into Iga on a mission to destroy every last Shinobi but due to the mountainous terrain and humidity the Shinobi headquarters was virtually inaccessible and Oda Nobua suffered a humiliating defeat against the Iga Shinobi. In 1581 Oda Nobunaga led an army 46,000 warriors to attack a force of less than 4,000 Iga Shinobi in order to annihilate the Shinobi forever. The sheer size of the army was too much for Momochi Sandayu’s Iga Shinobi to repel and the Iga Ryu Shinobi were defeated. Oda Nobunaga slayed large numbers of Shinobi and executed any survivors but many Shinobi fled the region and scattered themselves all over Japan with some allying themselves to Tokugawa Ieyasu. Momochi Sandayu was recorded to have fought with great courage but disappeared.

After the invasion of Iga, Momochi Sandayu travelled east to Kii Province where he disguised himself as a farmer until he heard the news of Nobunaga’s murder, by one of his own generals, on June 10th 1582. Momochi Sandayu returned to Iga and attempted to unite the Momochi and Hattori clans together but this attempt failed and much infighting between the two clans ensued. Eventually the clan leaders Momochi Sandayu and Hattori Hanzo dueled and Momochi Sandayu died by his student’s hands.

Momochi Sandayu’s advice to the men of his clan:

  • Never underestimate your enemies, always assume that they are dangerous.
  • Learn to slide your weight and move your body fluidly if you want to dodge your attacker
  • To achieve maximum efficiency moved the body as a unit, not by separate parts
  • Colorful movements and flourishes are unnecessary
  • Always attack vital and painful points. Use dodge and deception to get the right distance
  • Do not try to fight a superior force with more force, instead deviate its action by moving in the direction of its force to arrest and break it with its own strength.
  • Never lose sight of the enemy, even after a successful counterattack. Expect the unexpected from him and so you will survive
  • Always control the damage you are going to inflict on your enemy. Place the degree of punishment you are going to inflict according to the danger of the attack.




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