Koka ninja first appeared in the first year of the Choukyou era (1487.7.20-1489.8.21).
To suppress the rebel Sasaki Rokkaku clan, Shogun Ashikaga Kudai launched an invasion of the Rokkaku clan and attacked Koka castle. Members of Rokkaku clan secretly hid in the mountains and carried out guerrilla warfare.
This battle continued for 3 years until the death of Ashikaga Shogun the first year of the Entoku era (1489).
As a result of the war, the extraordinary abilities of Koka samurai (Koka ninja group) became well known through out the country.
Photo: A Shinto shrine sacred to Koka Sabro Kanie, who is the ancestor of the Koka Ninja.
5 years later, in the first year of the Meiou era in 1492, Ashikaga Yoshitane who succeed in strategy, commanded a general attack on Koka, but Sasaki Rokkaku clan under the protection of the Koka ninja, escaped to Ise through the Koka Mountains.
In the 11th year of the Eiroku era in 1568, Sasaki refused to obey orders from Oda Nobunaga and was captured. In the 9th year of the Tenshou era 1581, Nobunaga gathered an army of 46,000 in front of Azuchi castle and destroyed the Sasaki clan. With this, the Sasaki period was finished. During the crucial battle, the Koka Ninja’s allegiance shifted away from the Sasaki clan,leading to their defeat. Actually, this was Tokugawa Ieyasu’s plan. Ieyasu saw the potencial in ninja abilities from the beginning, and in the year 1558,in the Eiroku era, employed 270 Koka and Iga ninja. They say that the reason why ninja did not do anything when Sasaki was captured was that they received orders from Ieyasu.
An aggressive way of living was not in Koka ninja traditions. Mostly they used power to protect themselves. In the beginning Koka ninja supported the Sasaki clan and had a great influence on the history of Omi land. The Koka ninja were against Nobunaga’s intentions. The Ninja thought that Nobunaga overused his power and felt antipathy, to ward and him Nobunaga watched the Koka ninja with vigilance.
In the 10th year of the Tenshou era (1582), The Honnoji Incident (the forced suicide of daimyo Oda Nobunaga by his samurai general Akechi Mitsuhide on June 21, 1582) happened. A vassal of Nobunaga, Akechi Mitsuhide, suddenly attacked him in Honnoji and Nobunaga committed suicide. Ieyasu, who was invited by Nobunaga and was on the way to the capital when he heard news about Honnoji incident, immediately attempted to go back to Mikawa,however,Mitsuhide’s followers tried to hant Ieyasu down.
At that time, the Koka ninja used their favorite tactic for helping Ieyasu and led him through Ujitawara to Shigaraki where he stayed for one night with the Tarao family, one of the 53 Koka ninja Familes. There after Ieyasu was protected by Hattori Hanzo and other Iga Ninja. They went from Iga, crossed Kabuto,and came to the Ise seacoast. From the Ise Seacoast, they escaped to Mikawa. After that Iga ninja organization was established.
Among the three forerunners,in the struggle to control the entire country,the ninja expected that Ieyasu from Mikawa would be victories. Among all Daimyo in the Sengoku period (warring States period) Ieyasu used ninja’s service the most.
The migration of Koka ninja to Edo started in the 11th year of the Kanei era (1634), which was 50 years later than migration of the Iga ninja to Edo. Koka ninja continued the traditional parliamentary system.Additionally there was a strong opposition against moving to Edo from the motherland. However, in the end, the Ohara clan, a branch of the Koka Ninja clan and most of the Koka clan migrated to Edo with them.
Since the Sengoku period ninja learned the art of firearms. They became experts with guns and worked as soldiers. But after Ieyasu established Edo shogunate and enforced an idenfication system and hereditary system in Edo there was no need to learn art of ninja and ninja disappeared along with the change of generations. We can say that art of ninja was born in the mountains, grew up in the Sengoku period, and vanished in the Edo period.