Kamiya Koshijiro is the founder of the Kamiya dōjō, the creator of Kamiya Kasshin-ryū and the father of the dōjō's current master, Kamiya Kaoru and grandfather to Himura Kenji. After fighting in the bakumatsu on the side of the Ishin Shishi patriots, Koshijiro returned to his hometown of Tokyo and developed a kenjutsu style that would protect people rather than take their lives. However, he was drafted into the Seinan Wars and, in 1877, was though to have died on the battlefield, until a photograph and a letter by him was sent to Kaoru in 1883, revealing that he was alive and living in Hokkaidō, prompting Kaoru and her family to travel there in hopes of a reunion.


Kamiya Koshijiro was said to be a righteous, strong and honorable man, and benevolent at heart, having developed the sword that saves lives rather than continuing in the tradition of swords that kill.