In 1564, he was invited by Ieyasu TOKUGAWA to serve as his vassal, and in 1565 he had his first fight, the Battle of Anegawa, and after that he participated in many of Ieyasu's battles and achieved military exploits, and was praised by Ieyasu as a busho distinguished in military arts.
永禄7年（1564年）に徳川家康に招聘されてその家臣となり、永禄8年（1565年）の初陣を皮切りにして姉川の戦いをはじめ、家康の主要な合戦の多くに参戦して武功を挙げ、家康から武勇に優れた武将として賞賛された。