He then won the trust of Masatane Chiba and accepted Chiba's younger sister as his legal wife, strengthened the relationship with Muneie Chiba and the Gohojo clan, fought against Yoshiaki and the Satomi clan, and took the Hojo side and contributed to their victory in both of the two battles of Konodai.
その後は千葉昌胤の信任を受けてその妹を正室に迎え、千葉宗家や後北条氏との関係を強めて義明や里見氏と対抗、二度の国府台合戦ではいずれも北条方について勝利に貢献する。