Kagemori had a close relationship with Yasutoki HOJO, who became the third regent after the Jokyu War, and married off his daughter (Matsushita zenni) to Yasutoki's legitimate son Tokiuji HOJO; and his sotomago (grandchildren from his daughter married into another family) Tsunetoki HOJO and Tokiyori HOJO later became the regent in succession.
承久の乱後に3代執権となった北条泰時とは緊密な関係にあり、泰時の嫡子北条時氏に娘（松下禅尼）を嫁がせ、生まれた外孫の北条経時、北条時頼が続けて執権となった。