After the Mimasetoge Battle, although Ujimasa resisted Shingen's invasion of Izu and Suruga Provinces, castles in Suruga Province including Kanbara-jo and Fukazawa-jo Castles fell one after another, and also, Ujiyasu, a guardian of Ujimasa, became too sick to stay in the battlefront, and finally in 1570, Suruga Province was merged and virtually owned by Shingen except Kokokuji-jo Castle and a part of southern Sunto County which remained in the hands of the Hojo clan.
その後も信玄が伊豆・駿河方面に進出するとこれに対抗するが、蒲原城、深沢城等の駿河諸城が陥落し、後見役であった氏康が病がちになり戦線を後退、元亀元年（1570年）には北条方の駿河支配地域は興国寺城及び駿東南部一帯だけとなり、事実上駿河は信玄によって併合された。