Tsukamoto was born as the third son to a samurai named Inomichi Juzaemon of the Ogaki Domain (present day Gifu prefecture), and was adopted into the Tsukamoto family as a child. As a young samurai, he commanded a squad dispatched by the domain during the suppression of the anti-Shogunate forces in the Second Chōshū expedition; however, he later fought for the pro-imperial Satchō Alliance when the domain changed its alliance in the Boshin War. In 1872 he was commissioned as a second lieutenant in the fledgling Imperial Japanese Army. He was commander of the 6th Battalion during the 1874 Taiwan Expedition. Afterwards, he was stationed at the Kumamoto Garrison, and participated in suppression of the Satsuma Rebellion from February to October 1877.