Teacher to the Sword-Saint Shogun: How Kamiizumi Trained Ashikaga Yoshiteru

Ashikaga Yoshiteru (1536–1565), the thirteenth Muromachi shogun, is the only shogun in Japanese history given the epithet 'sword-saint shogun.' His sword ability was recognized by his daimyō contemporaries, and he was the unusual figure who, amid the warring-states upheaval, stayed in Kyoto and continued his sword training. Two names are transmitted as the teachers who developed Yoshiteru's sword talent: Tsukahara Bokuden and Kamiizumi Nobutsuna.

Yoshiteru's Sword Training

Yoshiteru is said to have begun sword training in his late teens after his appointment as shogun in 1546. He initially studied under Tsukahara Bokuden — through Bokuden's senior student Matsuoka Hyōgo-no-suke Norikata — and learned the Kashima Shintō-ryū. In the Eiroku period (1558–1570), when Kamiizumi Nobutsuna visited Kyoto, Yoshiteru also learned the Shinkage-ryū from him. He is the only shogun in history to have been directly trained by the two leading swordsmen of his generation. His sword talent reportedly developed into a personal synthesis of the two schools.

Kamiizumi's Kyoto Stay

Kamiizumi's stay in Kyoto is dated to around Eiroku 6 (1563), as a stop in his itinerant training en route to Yamato and Ise. Yoshiteru summoned Kamiizumi to the shogunal palace and received instruction in several sessions. Fragmentary records of Kamiizumi's visit survive in the contemporary court diary Tokitsugu-kyō Ki, corroborating that the sword instruction did in fact take place. Following this Kyoto stay Kamiizumi proceeded to Yamato Yagyū, where he would later award the Shinkage-ryū inka to Yagyū Munetoshi.

The Last Day at the Eiroku Incident

On May 19, 1565 (the nineteenth of the fifth month of Eiroku 8), the combined force of Matsunaga Hisahide and the Miyoshi Triumvirate raided the shogunal palace. Yoshiteru was twenty-nine. He thrust the famous swords of his house into the tatami around him and cut down attacker after attacker as they came in. Outnumbered, he was eventually killed, but the contemporary court diaries record him as having struck down more than ten men. The image of Yoshiteru in his final hour, as a sword master applying what he had learned from the two great swordsmen, became a standing reference point of later sword history.

What Kamiizumi's Involvement Left Behind

Kamiizumi's actual Kyoto stay was a matter of months, but as one of the teachers of the sword-saint shogun he was inscribed in history. As the first case of a contemporary sword school being directly recognized by a shogun, it had decisive significance for the later authority of the Shinkage-ryū. When Kamiizumi's student Yagyū Munetoshi's lineage later became the official sword of the Tokugawa shogunate, one of the grounds of its legitimacy was the fact that 'this is the school that taught the previous shogun.' A few months in Eiroku-period Kyoto determined the structure of warrior-class swordsmanship for the next two and a half centuries.

"The sword is not in form — it is in the heart."