When the Jokyu War occurred in 1221, Kagemori participated in the decision of most important policy as a member of leadership team of bakufu; and read the speech by proxy in which the ama shogun (nun warlord) Masako HOJO pled with gokenin for taking favorable actions as in the time of Yoritomo and ordered to subdue kyogata (the Kyoto side or supporters of the Imperial court in Kyoto).
承久3年（1221年）の承久の乱に際しては幕府首脳部一員として最高方針の決定に加わり、尼将軍北条政子が御家人たちに頼朝以来の恩顧を訴え、京方を討伐するよう命じた演説文を景盛が代読した。