Furthermore, he sent a messenger to Kenshin UESUGI with an aim to form a coalition against the Takeda clan, and he formed the Imagawa, Hojo and Uesugi alliance (the Etsu-So Alliance, or the Echigo and Sagami Alliance).
また、武田氏への共闘を目的に上杉謙信のもとに使者を送り、今川・北条・上杉三国同盟を結ぶ（実態は越相同盟）。