From boyhood into his twenties Tadamasa went through the usual training in arms: the sword, jūjutsu and gunnery. For learning he went to the school of Asaka Gonsai, which was kept inside the residence at Surugadai. Ōtsubo Motoji's Oguri Kōzukenosuke Tadamasa Kakei oyobi Ryaku-nenpu records his masters in arms as follows.
Swordsmanship — the Jikishinkage school, which derives from the Shinkage school. He studied under Onogai Shimotsuke-no-kami Nobutomo (Seiichirō), and afterwards, it is said, under Fujikawa Seisai.
Jūjutsu — Kubota Kintarō (handed down also as Kubota Sukedarō).
Gunnery — the Japanese school, under Tamura Kazue.
That the gunnery is set down as “the Japanese school” is worth noting: what Tadamasa learned was gunnery in the old Japanese manner. In those same years, at Tokumaru-ga-hara outside Edo — Itabashi today — Takashima Shūhan was giving public drills in Western gunnery and astonishing those who watched. Tadamasa came to deal seriously with Western guns only much later, as commissioner of infantry and acting commissioner of the army, when he pushed the three-arm system forward.
Swordsmanship — he did not choose a fashionable school
Trace the Jikishinkage school back and it reaches Kamiizumi Ise-no-kami Hidetsuna, founder of the Shinkage school. From him the Yagyū school of Yagyū Sekishūsai Muneyoshi and the Shin'ei school of Okuyama Kyūgasai branched off, and from the latter came the Jikishinkage school of Yamada Heizaemon Mitsunori.
The man who made the school's name was Naganuma Shirōzaemon Kunisato, who brought off a technical change in swordsmanship. The bamboo sword was invented by Kamiizumi Ise-no-kami, but his was no more than a shinai: a round length of bamboo, split fine at the tip and bound, used in place of a wooden sword. It was Naganuma who used the shinai of four split staves that is used today, and who invented and improved the mask, the gauntlets and the breastplate. His school at Shiba Nishikubo met obstruction of every kind from the other schools and was abused roundly. Before long, though, the same men were using armour and shinai themselves, and the schools of Edo came suddenly alive.
In Tadamasa's boyhood Edo was in an unprecedented boom of neighbourhood fencing schools. He did not pick one of the fashionable ones. He trained at a school of a line that held an old tradition and had changed its technique in pursuit of what worked. Sakamoto Fujiyoshi's Oguri Kōzukenosuke no Shōgai notes that Tadamasa himself turned down the celebrated swordsman Shimada Toranosuke, takes it that his own intent counted heavily in the choice of school, and writes that “Tadamasa hated the counterfeit and the bluff”.
Out of Onogai Seiichirō's school came swordsmen of the first rank in those years: Shimada Toranosuke, Yokokawa Shichirō, Sakakibara Kenkichi, Amano Hachirō. Katsu Rintarō — Kaishū — was at this school of Onogai's as well, until he moved to Shimada's at fifteen.
Onogai is said to have watched Tadamasa fence in later years and praised him in these words.
Who would have thought that this man's swordsmanship would reach so fine a point.
Which master granted him full certification is not agreed in the sources: one tradition gives Fujikawa Seisai, and there are others. What is clear is that he did not enter a fashionable school, and that he studied the Jikishinkage school and was certified in it.
The family's own “Oguri school”
The Oguri had a martial art of their own, the Oguri school, and an unusual one: an irregular swordsmanship that combined grappling methods and jūjutsu with the sword.
Traced back, it reaches Kamiizumi Ise-no-kami Hidetsuna of the Shinkage school, as the Jikishinkage school does. Two lines branched from Yagyū Sekishūsai Muneyoshi's school: one carried on as the orthodox Yagyū school through Yagyū Munenori, Mitsuyoshi and Munefuyu, and the other, the collateral line, was the Oguri school. Oguri Niemon Nobuyoshi, a son of the founder Oguri Tadamasa, studied the sword under Yagyū Muneyoshi and worked the school out by joining jūjutsu to it.
Putting together what had been thought wholly separate, he opened a new and practical way of fighting; the originality of it told, and in the 1620s and 1630s the school swept the age. Daimyo and hatamoto entered it one after another, its pupils reached three thousand six hundred, and matches were held before the shogun.
It was Asahina Hanzaemon who spread the Oguri school in Tosa in the last years of the shogunate, and Sakamoto Ryōma who studied it there from boyhood. Ryōma and his elder sister Otome both went daily to the school of Hineno Benji of the Oguri line. In the first month of 1853, at seventeen, Ryōma received from Hineno the Oguri-ryū Wa-heihō Ji-mokuroku, a catalogue of the school's methods; in 1854, one scroll each of the twelve articles and the twenty-five articles of its method; and in 1861, one scroll of its three articles.
Tadamasa and Katsu Kaishū were linked by the same fencing school; Katsu had a decisive influence on Ryōma; and Ryōma learned the sword in a school that carried the Oguri name. Follow the lines of descent in swordsmanship alone, and three of the men who moved the last years of the shogunate turn out to be tied together by threads no one sees.
Sources: Ōtsubo Motoji, Oguri Kōzukenosuke Tadamasa Kakei oyobi Ryaku-nenpu (the genealogy and short chronology of Oguri Kōzukenosuke Tadamasa), Oguri Kō Kenshōkai, 1957; Sakamoto Fujiyoshi, Oguri Kōzukenosuke no Shōgai (the life of Oguri Kōzukenosuke), Kōdansha, 1987
→ The Oguri school of swordsmanship and an unexpected link with Sakamoto Ryōma → Katsu Kaishū → Asaka Gonsai's school