Shifting from Jūjutsu to Gunnery

When the 8th domain lord Sanada Yukitsura, who ordered construction of Bunbu Gakkō, assumed the position as a senior councilor of the Tokugawa shogunate, he was preoccupied with external relations as an official in charge of coastal defense. In his domain of Matsushiro, he took the lead in a military system reform to equip the domain with Western armaments.
A group of several dozens of retainers, including Sakuma Shōzan, learned the latest techniques under Egawa Tarōzaemon, a vassal of the shogun, and began manufacturing Western firearms and cannons in Matsushiro. Meanwhile, one of the retainers by the name of Sakuma Yōzaemon created the Oie school of gunnery (a.k.a. Sanada school).
Likewise, Bunbu Gakkō issued an order to its pupils to study gunnery without exception, in addition to either kenjutsu swordsmanship or sōjutsu spearsmanship, with the result that they began offering fewer classes on kyūjutsu archery and jūjutsu, until finally the Judo Hall was converted into the Daijū Cannon Factory in 1868 and jūjutsu practice was ended completely.
Records say that a total of 5,716 and 935,849 rounds of ammunition were used for cannons and rifles, respectively, in the Boshin civil war (1868-1869). Historical records dated May 1870 say that the Matsushiro Domain had 53 cannons and 2,325 rifles, which suggests that the Matsushiro Domain still had a large stock of firearms.
Maejima Genzō Kazumasa held various posts, including bugyō magistrate, metsuke superintendent officer, and jōbikeshiyaku fire fighter, and mastered the Ogino school of gunnery. He was also the Matsushiro Domain's grand master of gunnery.
The former Maejima Family Residence is a Nagano Prefectural Treasure.