In rivalry with the Koetsu Alliance, Ujimasa built a new alliance with Nobunaga ODA and Ieyasu TOKUGAWA by reversing the Second Koso Alliance, and invaded the territory of the Takeda clan in Suruga from both sides.
甲越同盟に対して氏政は第2次甲相同盟を破棄し、織田信長・徳川家康と同盟を結び駿河の武田領国を挟撃する。