Shigemori's mother was of low birth and he therefore did not have any powerful relatives that could support him, and also, his younger brother by the same mother, Motomori, died young, and these facts are believed to have deepened Shigemori's loneliness.
重盛の母は身分が低かったため、支えてくれる有力な親族を持たず、同母弟の基盛が早くに死去していたことも、重盛の孤立感を深めたと推測される。