was a samurai retainer of the Oda clan. He was also called and was referred by the title of . Initially he had the family name of , but in 1575 received the name of a respected clan, Harada, which he took as his own. As of 1574, Naomasa took part in military actions and in 1575, he joined the sieges of Nagashima, a crackdown on the Ikkō-ikki rebellions in Echizen Province.