Yui Shōsetsu

由比正雪

Instigator of the Keian Incident—an early Edo-period military scholar who opened the military science school Chōkōdō

Era

Early Edo Period

Lifespan

1605-1651

Associated Sword Tradition

Kusunoki-ryū military science (said to have been learned from Kusunoki Fuden)

Description

Instigator of the Keian Incident

Yui Shōsetsu, born in Suruga Province in Keichō 10 (1605), was a military science scholar who planned the Keian Incident (1651), the most dangerous anti-Tokugawa movement of the early Edo period. In Edo he opened the military science school Chōkōdō and gathered many disciples.

Shōsetsu the Military Scholar

Although there are various theories about Shōsetsu's career, the Edo-period popular narrative Keian Taiheiki and other works state that he studied under Kusunoki Fuden, a military science scholar who claimed to be a descendant of Kusunoki Masashige, and succeeded to his school.

Chōkōdō

The military science school Chōkōdō, which Shōsetsu opened in Kanda Renjaku-chō in Edo, took its name from Zhang Zifang and Zhuge Kongming, famous Chinese strategists, and many hatamoto and domain retainers became its disciples. Rōnin who increased due to the forfeiture of daimyō domains also gathered around Shōsetsu, and it is said that the rōnin among the Keian Incident conspirators reached about 1,500.

The Course of the Keian Incident

Following the death of shogun Tokugawa Iemitsu in the 4th month of Keian 4 (1651), Shōsetsu planned simultaneous uprisings in Sunpu, Edo, Kyoto, and Osaka. However, in the 7th month of the same year, the plan was discovered in advance through a complaint by a member of the conspirators, and Shōsetsu was surrounded at his lodging in Sunpu by yoriki and dōshin under the town magistrate. Having lost his means of escape, Shōsetsu killed himself, and the plan ended as an unrealized attempt. However, the incident gave a serious shock to the Tokugawa shogunate and became an occasion prompting policy responses to the rōnin problem, such as easing the ban on deathbed adoption (matsugo yōshi).