What is the Soma Daisaku incident? Attempted attack on the Tsugaru Domain lord of a Nanbu Domain samurai, who is considered to be Michinoku Chushingura [Iwate Prefecture]

The "Soma Daisaku Incident" occurred over 200 years ago on May 24, 1821 (April 23, 1821) when samurai from the Morioka domain Tsugaru Yasuchika failed.

is called "Soma Daisaku Incident" the mastermind, Shimotomai Hidenoshin, a samurai from the Morioka domain, called himself "Soma Daisaku"

It was passed down as a story in the Edo period and was hailed by the public a "reincarnation of the Ako Roshi." It has also been featured in modern films and TV dramas, and "Michinoku Chushingura" was published in 2009.

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The root of the incident was a feud between the Nanbu and Tsugaru clans

reached its peak during the Sengoku period under Nanbu Harumasa , the 24th head of the Sannohe Nanbu clan expanding his territory to the point that it was said that "Nambu territory lies before the crescent moon is full."

, Oura Tamenobu (later Tsugaru Tamenobu) a member of the Nanbu clan, raised an army and declared independence, resulting in the loss of the Tsugaru region and the Sotogahama region (along the Mutsu Bay coast).

The skillful diplomatic maneuvering of Oura (Tsugaru) Narinobu

Narinobu consolidated his control over the Tsugaru region and attempted to go to Kyoto himself to show his submission to Toyotomi Hideyoshi, but failed. However, in 1589 (Tensho 17), he led his vassals to Kyoto and was granted his territory by Hideyoshi, the ruler of Japan

Nanbu Nobunao, who succeeded Harumasa, filed a complaint with Hideyoshi through Maeda Toshiie , alleging that the Sobujirei (General Peace Order) , which prohibited private fighting among daimyo, and seized territory.

Although there was a movement to punish Narinobu at one point, he had already shown his submission and had met with Hideyoshi before Nobunao during the Siege of Odawara, so his territory in Tsugaru was assured. Narinobu was skilled at diplomatic maneuvering, never failing to give gifts to important people and Konoe Sakihisa , to become his adopted son, making him Hideyoshi's formal brother-in-law.

By the way, when Narinobu became Maehisa's adopted son and was given the Fujiwara surname, he changed his surname from Oura to Tsugaru

The Nanbu and Tsugaru clans became enemies

In the Battle of Sekigahara in 1600 (Keicho 5), both clans sided with the Eastern Army of Tokugawa Ieyasu, and Tsugaru Narinobu led troops to take part in the siege of Ogaki Castle, but Nanbu Nobunao remained in his own country

However, Naritsugu's eldest son, Nobutake, was a page to Toyotomi Hideyori and joined the Western Army, and it is said that this was because Naritsugu was trying to survive, just like the Sanada clan. Perhaps because of this, although the Tsugaru clan received little increase in their fief after the war, they were granted their territory by the Tokugawa shogunate and founded the Hirosaki Domain

In addition, Nanbu Nobunao was granted Waga County and Hienuki County (Iwate Prefecture) in place of the three Tsugaru counties, and became the Morioka Domain, but in reality his territory was reduced, which caused growing dissatisfaction among the Nanbu family's vassals

The feud between the two clans became decisive, and continued to deepen with frequent border disputes occurring thereafter

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What kind of person was Soma Daisaku?

Hidenoshin's real Shimotomai Masazane , and he later took the name "Soma Daisaku" because the Shimotomai clan was considered to be a descendant of the Soma clan, which was itself a descendant of Taira no Masakado.

The Shimotome clan was a vassal of the Nanbu clan, whose territory was Fukuoka in Mutsu Province (Ninohe City, Iwate Prefecture), and Hidenoshin, the second son, went to Edo at the age of 17 (there is a theory that he ran away from home) and studied martial arts under the hatamoto (samurai) Natsume Choemon

In 1808 (Bunka 5), ​​Natsume was sent to Etorofu Island with 2,000 Sendai domain soldiers to respond to the Russian attack on Ezo, but Hidenoshin was entrusted to the dojo of Natsume's master, Hirayama Gyozo, and became his assistant instructor

Hidenoshin feels a growing sense of crisis over Russia's aggressive actions

When Natsume Choemon returned from Ezo, he told Hidenoshin about the situation there. Hidenoshin heard from Natsume that the Japanese soldiers were all outdated and poorly trained, and could only watch as the Russian army attacked. This made Hidenoshin keenly aware of the importance of guarding the north

opened called Seiheikaku, which emphasized "simplicity and strength" to educate the children of the domain

It is said that he had as many as 200 disciples, and an auditorium, a martial arts hall, a riding arena, and a swimming training ground were built. Hidenoshin is said to have preached to his disciples that they must "protect Japan from Russian invasion," and to have also inspected Ezo

Former site of the Heiseikaku Martial Arts Training Hall <Information>

• Name: Heiseikaku Enbu Hall Ruins
• Address: 95 Kindaichi Shintano, Ninohe City, Iwate Prefecture

Google Map

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The Hirosaki Domain's rising status and the Morioka Domain's decline

The relationship between the Tsugaru and Nanbu families is such that in 1805 (Bunka 2), the 9th lord of the Hirosaki Domain, Tsugaru Yasuchika, was appointed a chamberlain of the rank of Junior Fourth Rank, and the 10th lord of the Morioka Domain, Nanbu Toshitaka, was of the same rank, so their family status was equal

Toshitaka attempted to raise his family's status by offering part of the Nanbu domain to the shogunate in order to defend the Emishi, but the matter became complicated and he incurred the shogunate's displeasure, so the gap between his family and the Tsugaru family was not bridged

In 1820 (Bunsei 3), Toshiyoshi died at the age of 39 and was succeeded by Toshimochi, but because he was young and had no rank or official position, the Nanbu family's ranking within Edo Castle further declined. The Morioka domain samurai became increasingly dissatisfied because the Tsugaru clan, which was their vassal, had a higher status, and it was said that Toshiyoshi's early death was due to long-standing resentment towards the Tsugaru clan

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The progress of the Soma Daisaku incident

Unable to contain their dissatisfaction with the Tsugaru clan, Hidenoshin and other samurai from the Morioka domain sent a "challenge letter" to Yasuchika demanding that he resign from his post and retire, and if their demands were not met, they threatened to assassinate him, saying, "We will avenge our humiliation and resentment."

However, his request was ignored, and Hidenoshin planned to attack Tsugaru Yasuchika, who was returning from his alternate attendance in 1821 (Bunsei 4), near Shirasawa Station (Odate City, Akita Prefecture) in the territory of the Akita domain

Hidenoshin and other Morioka samurai prepared homemade cannons and guns and waited, but Yasuchika returned home by a different route after being betrayed by his companion, and the attack ended in failure

Hidenoshin's escape

Hidenoshin fled the Morioka domain with his wife and children and went to Edo, where he changed his name to Soma Daisaku, but was captured and beheaded the following August, 1822. A grave for his head remains at Myoenji Temple in Honjo Azumabashi, Tokyo, as the head priest at the time was Hidenoshin's uncle

In addition, in October 1852 (Kaei 5), Kan'onji Temple was built in Morioka to commemorate Hidenoshin, with Hidenoshin's son becoming the first chief priest, and a stone monument in his honor was erected within the temple grounds

Soma Daisaku Incident Historical Site ＜Information＞

• Name: Historic Site of the Soma Daisaku Incident
• Location: Bridge girder, Odate City, Akita Prefecture
• URL: Odate Local Museum official website

Google Map　

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Kangeonji Temple＜Information＞

• Name: Nichiren Shoshu Enisan Gamenji Temple
• Address: 1-22-79 Minamisenboku, Morioka City, Iwate Prefecture
• Phone number: 019-636-0549
• URL: Gameunsa Temple official website

Google Map

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The Nanbu and Hirosaki Domains after the incident

Nanbu Yoroi was appointed Daizen-no-taifu (Grandmaster of the Diet), Junior Fourth Rank, in December 1812 (Bunsei 4), the year the incident occurred, finally bringing him on a level with Tsugaru Yasuchika in rank. However, Tsugaru Yasuchika retired a few years later, reportedly in poor health after returning from the failed attack, and Hidenoshin and his men's goal was ultimately achieved

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summary

Soma Daisaku was executed as the ringleader of the attack on the lord of Hirosaki Domain, but his actions, full of zeal and compassion in opposing Russian aggression, left a lasting impression on many people in later generations. Fujita Toko, who preached the idea of ​​revering the emperor and expelling the barbarians in the Mito Domain at the end of the Edo period, praised his righteousness, and Yoshida Shoin of the Choshu Domain composed a long poem in memory of Hidenoshin

Subsequent research has suggested that Hidenoshin's true intention was not just to show loyalty to the Nanbu family, but also to encourage Tsugaru and Nanbu to reconcile and cooperate in guarding the north

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