During the 1580s, when the lord of Yamagatajo Castle, Yoshiaki MOGAMI, who was rapidly expanding his territory, launched an attack on the Shonai district, the lord of Ourajo Castle, Yoshiuji DAIHOJI, confronted Mogami's troops with the help of Shigenaga HONJO, who had been an alliance from the days of his father Yoshimasu DAIHOJI.
1580年代、急速に領土を拡大していた山形城主最上義光の攻勢がついに庄内にも及ぶようになると、尾浦城主大宝寺義氏は父・大宝寺義増の代からの盟友本庄繁長の支援を受けてこれに対抗した。