Kōga-Ryū

Founding of the Kōga-Ryū

The Kōga-Ryū Ninjutsu was the other Ninja clan of great importance in Japan. It was founded by 53 families, probably in the Tenkyo period between 938 and 946.

After Mochizuki Saburi Kameie distinguished himself in the war against the Taira no Masakado, he was given some land southeast of Omo Province. The region was called Kōga Gun, so Mochizuke changed its name to Kōga Oni no Kami Kameie. It was his son Oni no Kami Iechika, a talent in the military arts and in literature, who is said to have founded the Kōga-Ryū. He is said to have learned genjutsu (the art of illusion) from the Buddhist monk Tatsumaki Hoshi who lived in the area.

The tradition endured for seven generations, Oni no Kami Ienari, Iesada, Ienaga, Iekiyo, Ietoo, Ieyoshi, and Yoshiyasu, before expanding to other families, Mochizuki, Ugai, Naiki, and Akutagawa. These five families were joined by the remaining troops from the north and south of the kingdom during the Namboku War (1335-1395). With the help of the Kōga-Ryū, they grew to 53 families. Some of these families of the Kōga-Ryū were:

Koga-ryu, Shinpi-ryu, Taira-ryu, Isshu-ryu, Byaku-ryu, Tengu-ryu, Taro-ryu, Kuruya-ryu, Tomo-ryu, Tatara-ryu, Sugawara-ryu, Otomo-ryu, Hiryu- Ryū, Fujiwara-ryu, Sasaki-ryu, Tachibana-ryu, Kawachi-yon-tengu-ryu.

The Leaders of the Kōga-Ryū

As the Kōga-Ryū grew, there were eight families that controlled the other Ryū in Kōga. These eight families were Kōga, Mochizuki, Ugai, Naikii, Akutagawa, Ueno, Ban and Nagano. But also groups in Kōga like Hiryūgumi, Kakuryūgumi, Tachibana Hachitengu Gumi, and Kawachi Yon Tengu Gumi had very capable masters.

During the Hokuto period (1441-1451), the leaders were Koga Saburo, Mochizuki Goro, Ugai Ryūhoshi, Naiki Fujibe, and Akutagawa Kazuma. During the Bunmei period (1469-1487), it was Kōga Saburo II, Mochizuki Yajiro, Ugai Chiaki, Naiki Gohei, and Akutagawa Tenpei who were from the Sasaki family who were the Daimyō (Big Name, wealthy landowner) in this area, were recruited to lead the troops against Ashikaga Yoshizawa.

Almost 100 years later, the Sasaki family recruited Ninja again. This time it were Ninja from the Kōga and Iga regions in 1570. They also recruited Samurai from Kōga with the aim of destroying Oda Nobunaga. The Samurai were trained intensively for a short period of time so that they could execute the combat strategies of the jōnin.

Sasaki’s army was divided into three divisions, the first being led by Ninja of Mikumo-Ryū, Takanose-Ryū, Mizuhara-Ryū, and Inui-Ryū. The second was led by the other 53 Kōga families and the third was by the Samurai Sasaki. In the battle, Mikumo Iyo Kami, who was leading one of Sasaki’s armies, suddenly switched sides and attacked Sasaki’s army from the rear, resulting in their defeat. Sasaki himself barely escaped.

Tokugawa Ieyasu Deploys Kōga Ninja

When Tokugawa Ieyasu was fighting for power in Japan, Fushima Castle near Kyōto was under siege. They had to defend themselves against the armies to the west long enough to give the Tokugawa army enough time to regroup to fight at Sekigahara (site of the civil war’s final decisive battle) to the east. 400 Ninja of the Kōga region helped defend it. Some of them were inside the castle, others terrorized the enemy outside with various attacks. About 100 of them died, and after Tokugawa was victorious, they held a ceremony and it is mentioned that Mochizuki and Arakawa were killed.

The Last Mission of the Kōga Ninja

One of the last times the Kōga Ninja became active was at the battle of Shimabara no Ran (site of the battle in the Christian Rebellion), when Christian Samurai started a rebellion and seized the Hara Castle in Shimabara province on Kyushu occupied. Ten Ninja from the Kōga region were sent by Izumo Kami Nobutsuna to gather information for the Shōgun’s Samurai to prepare to attack the castle.

They were led by Mochizuki Heidayu, 63 years old, and Akutagawa Kiyouemon, 60 years old, both veterans of the Battle of Sekigahara. The others from Kōga were:

  • Ivane Kanbei, 56 years old
  • Tomei Gohei, 53 years old
  • Natsumi Kakunosuke, 41 years old
  • Akutagawa Shichirobei, 25 years old
  • Kamogai Kanuemon, 56 years old
  • Ivani Kanbei, 45 years old
  • Mochizuki Yoemon, 33 years old
  • Yamanaka Jutaya, 24 years old

They arrived on January 4th, 1638 and their first task was to make a map of the area around the castle. Just 15 days later, they sent a detailed map of the castle and forces to Edo (present-day Tōkyō) to the shogun Tokugawa Iemitsu.

It is also said that the Ninja from Kōga, or ongyo no mono (hidden persons) as they were also called, snuck into the castle every night without any problem. On January 21, they stole food from the castle as their food supplies were running low. They also managed to learn some secret passwords.

On January 27, five Kōga Ninja managed to get into the castle disguised as soldiers. They were Mochizuki Yoemon, Arakawa Shichirobei, Natsume Kakanosuke, Yamanaka Jutayu, and Tomo Gohei. The besiegers fired their firearms, and the enemies snuffed out their torches so they could no longer hit. Late that night, as the guards began to relax, the five climbed over the walls under cover of darkness.

Arakawa didn’t pay enough attention and fell into a hole, Mochizuki immediately rushed to his aid. But because of the noise, the guards immediately lit the torches again, and they were spotted. Mochizuki and Arakawa ran through the troops, grabbing one of the Christian flags along the way, and were decided. All five managed to escape, but Mochizuki and Arakawa were wounded.

When the castle was attacked on February 24, the Kōga Ninja served as liaisons between the units. Incidentally, Miyamoto Musashi (the most famous swordmaster in Japan) helped the shogun plan the battle. But he was hit by a rock thrown from the wall by a woman and had to retreat, complaining about the loss of his youthful vigor.

The Last Kōga Ninja

It is said that the Kōga-Ryū survived until the middle of the 20th century through Fujita Seiko (1899-1966). He is said to have been the 14th soke of the Kōga-Ryū. During World War II he led small units in the jungles. At the Tokyo Olympics in 1964, he tried to get athletes to train using Ninja methods. At the time, he drew attention to himself with spectacular demonstrations. Fujita Seiko died of cirrhosis of the liver at his home in Tōkyō on January 4, 1966, at the age of 67. He was the Grand Master of Kōga Ninja Ryū Jūjutsu and the 14th soke of Sato Ryū kenpō. According to official information, he never passed on a license to teach the Kōga-Ryū to students.

There is a book called Ninjutsu no Gokui written by Gingetsu, who learned the techniques and history from Tanemura Ihachiro, a jōnin of the Kōga-Ryū. The techniques described in this book are very similar to those of the Iga Togakure-Ryū.


Text: Peter CarlssonTranslation: Stefan Imhoff