In the Battle of Toba-Fushimi, whereby the Boshin War started, Tomozane made great achievements by leading an army himself and defeating the bakufu army, and in 1869, was awarded shotenroku (a premium) of 1,000 koku (approximately 180 cubic meters of rice).
戊辰戦争の緒戦である鳥羽伏見の戦いでは、自ら兵を率いて幕府軍を撃退するなど多大な功績をあげ、1869年、賞典禄1000石を授けられた。