Shōin Yoshida was born on 20 September 1830 in Hagi, the second son of Sugi Yurinosuke Tsunemichi, a samurai of the domain of Choshu. His personal name was Norikata, his common name Torajiro, and he went by such literary names as Shoin and Nijuikkai Moshi. He was adopted by his uncle Yoshida Taisuke, a teacher of the Yamaga school of military science, at the age of four and became the heir of the family the following year. He also received instruction from another uncle, Tamaki Bunnoshin.
He was a very apt pupil and at the age of nine lectured on military science in the presence of the lord of the domain. By the age of seventeen, he was acknowledged as an expert in the teachings of the Yamaga school and the following year became an instructor in his own right.
In 1850 he made a tour of Kyushu and in 1851 accompanied the lord of his domain to Edo, where he made many friends and came under the influence of various teachers. Among the latter, his contacts with Sakuma Shozan, an advocate of Western learning and military science, were particularly important. He became Sakuma's disciple and remained deeply under his influence for the rest of his life.
While in Edo, he slipped away from the domain residence and embarked on a tour of northeastern Honshu, visiting the domain of Mito and coming under the influence of the Mito scholars and patriots. But on his return to Edo, he was accused of traveling without proper permission and was ordered to return to Hagi, where he was deprived of his stipend and samurai status. He'was soon forgiven by the lord of the domain, however, and was given permission to spend the following ten years traveling about to other areas to study. In 1853 he embarked once more on a series of travels that took him back to Edo. The same year, Perry appeared with his squadron of ships at Uraga and began pressing for the opening of the country. Shoin went to Uraga to observe the foreigners and, becoming more convinced than ever of the superiority of Western style armaments, determined to travel abroad. He hastened to Nagasaki at the news that a Russian official party had put into port there, only to find on his arrival that the Russians had already departed. He returned to Edo, and in 1854, when Perry appeared once more, he and a disciple named Kaneko Jusuke went to Shimoda and attempted to stow away on one of the American warships, but they were apprehended and placed under arrest.
Shoin was sent back to Hagi, where he was placed in confinement. For the following five years until his death, he devoted his time to writing and teaching. He was released from prison in 1855, transferred to house con-finement, and in time opened a small private school called the Shoka Sonjuku on the grounds of the house where he was confined. There he gave instruction to a large number of disciples, at the same time vigorously supporting the sonno-joi movement, which called for the expulsion of the foreigners and the restoration of power to the emperor. His students included such promising young men as Takasugi Shinsaku, Kusaka Genzui, Ito Hirobumi, and Yamagata Aritomo, who later played important roles in overthrowing the Tokugawa shogunate and carrying out the Meiji Restoration.
Fired by hatred for the shogunate and patriotic zeal, Shoin conceived the idea of assassinating the high shogunate official Manabe Akikatsu. Word of the plot leaked out, and the domain authorities, fearful of being implicated, placed him under arrest once more. Meanwhile, the shogunate learned of the affair, and Shoin was sent to Edo and imprisoned there. It was the time of the Great Persecution of the Ansei era, when the shogunate was taking the harshest measures against its adversaries. Shdin was executed in 1859 at the age of twenty-nine. In time two shrines were established to pay honor to his spirit, one in Hagi and the other in Setagaya Ward in Tokyo.