Hirayama Kōzō

Hirayama Kōzō (1760-1829) was a shogunal retainer, military scholar, and martial artist who was active in the late Edo period. A master of the eighteen martial arts, including swordsmanship, spearmanship, archery, and horsemanship, he exerted enormous influence on the warrior society of his time. Together with Mamiya Rinzō and Kondō Jūzō, he was known as the "Three Zō of Bunsei," and he was active as a standard-bearer of the revival of martial arts in the late Edo period.

Kōzō was born in Yotsuya, Edo, as the son of a gokenin (lower-ranking retainer of the Edo shogunate) serving as a dōshin of the Igagumi. Since childhood he showed a strong interest in and talent for martial arts in general. He studied swordsmanship under Yamada Shōsai of the Shinkan-ryū, and also trained in Naganuma-ryū military science, Ōshima-ryū spearmanship, Shibukawa-ryū jūjutsu, and Buei-ryū gunnery. Later he founded the Chūkō Shinkan-ryū (later renamed Kōbu Jitsuyō-ryū), and while teaching swordsmanship, military science, and Confucianism at the dōjō in his home, he deepened his own theories of military science and martial arts. In Edo at the time, the warrior class had been drifting away from martial arts under the long-running civil governance, but Kōzō actively sought to correct this situation as a "return to the true form of the samurai."

What makes Kōzō especially notable is his thoroughgoing practical-combat orientation and his theoretical approach to martial arts research. Holding the conviction that samurai should cultivate both the civil and the martial ways, he studied widely the martial and military texts of past and present, and never neglected actual martial training. His writings number 500 volumes, including Kensetsu, Kenchō, Sonshi Engi, and Kaibō Mondō. When Russians appeared in the north in Bunka 4 (1807), he took a strong interest in coastal defense, and he petitioned the shogunate to be allowed to cross to Ezo himself to prevent their southward advance.

In relation to Japanese swords, Kōzō also contributed greatly to the systematization of practical swordsmanship and sword technique. Having mastered several swordsmanship schools, he explored the most effective swordsmanship for actual combat while comparing and analyzing the characteristics of each school. It is said that although Kōzō was short in stature, he wore an unusually long sword of 3 shaku 8 sun (about 115 cm), and that he never failed to practice drawing a 4-shaku iai sword 200 to 300 times every morning. Kōzō, who was both a theorist and a practitioner of martial arts, pursued the essence of the Japanese sword not as a mere craft object but as the soul of the warrior and a tool for actual combat.