三方原之戰
Towards 1564, he married Yamanote-dono (山手殿), a daughter of Uda Yoritada, who was a local lord of Tōtōmi Province. Later she gave birth to his two sons Nobuyuki and Nobushige. During this period, he participated in many battles under the Takeda clan, including the Fourth Battle of Kawanakajima (1561) and the Battle of Mimasetōge (1569). Also most importantly, from 1572 onwards, he joined Shingen in his campaign towards Kyoto against the Oda and Tokugawa clans and took part in the Battle of Mikatagahara (1573).