Masatoyo was one of Takeda Shingen's most reliable generals and fought in many of his battles. In 1566 he was given Minowa Castle in Kôzuke Province after it fell to the Takeda. At Mikatagahara he led a charge into the Tokugawa ranks and was at the forefront of the fighting at Nagashino (1575). He had opposed the attack at Nagashino and in the course of the battle was shot many times by arrows before being beheaded by Asahina Yasukatsu. He had been noted for his warm disposition and his equally impressive talents in warfare and administration.