Son of Taira no Tadamori and half-brother of Kiyomori. His mother was Ike no Zenni (Fujiwara no Muneko), famously known for persuading Kiyomori to spare the young Minamoto no Yoritomo after the Heiji Rebellion (1159), commuting his sentence to exile in Izu. Yorimori maintained a delicate distance from Kiyomori while holding high court rank. When the Taira fled the capital in 1183, Yorimori stayed behind—reportedly because of the debt Yoritomo owed his mother. Yoritomo indeed treated him generously, confirming his estates. One of the very few Taira to survive the clan's near-total destruction, he symbolizes how a mother's compassion altered the course of fate.

A cautious figure who maintained an independent position within the clan. Harboring complex feelings toward his brother Kiyomori, he followed his mother's guidance and developed a flexible approach to survival.

Ike no Zenni's rescue of Yoritomo is one of the turning points of Japanese history, and that debt saved Yorimori's life. It is remembered as a rare case where a mother-son bond changed the course of history.