Although he at first served Mochiuji ASHIKAGA of Kamakura Kubo (Govener - general of the Kanto region), Ujiyori became loyal to the Muromachi shogunate during the Eikyo War, coming under the command of the Uesugi clan.
初め鎌倉公方足利持氏に仕えていたが、永享の乱の際に室町幕府方に付いて上杉氏の指揮下に入る。