Soon he lost Yoshida-jo Castle (Mikawa Province) and lost the dominion of Mikawa, he was disregarded by the Takeda clan to which he allied, the tripartite alliance was renounced unilaterally, and Suruga was in danger of invasion by the Takeda clan.
やがて吉田城(三河国)を失陥、三河の支配権も喪失すると、同盟関係の武田氏からも侮られて、三国同盟の一方的破棄から武田氏による駿河侵攻に晒される。