For this son-in-law-relationship, when Yoshitaka OUCHI was killed in the rebellion by Shugodai (deputy military governor) Takafusa SUE and replaced by Yoshinaga OUCHI as head of Ouchi family, Masayori raised his own army to fight against the Sue's army.
その関係もあり、大内義隆が守護代陶隆房の謀叛によって死亡し、大内氏を大内義長が継ぐと、これに反発して反陶の兵を挙げ、陶軍と戦っている。