As Munemori was raised as nobility earlier than Kiyomori and Shigemori, it can be surmised that Munemori received privileged treatment as the firstborn child of Tokiko, his father's lawful wife.
叙爵の年齢は清盛・重盛より早く、正室・時子の長子として優遇されていた様子がうかがえる。