Born in 1104 into the distinguished Settsu-Minamoto line, Yorimasa excelled in waka poetry and archery. In 1168, at the age of 77, he was raised to Junior Third Rank, becoming known as the first samurai of the Minamoto to reach the courtier class. He is also famous in legend for slaying the nue, a mythical chimera. In 1180, outraged at Taira tyranny, he raised the banner of rebellion in support of Prince Mochihito, a son of Retired Emperor Go-Shirakawa. Cornered in the Battle of the Uji River, he took his own life at Byōdōin. He was 77. The rising he sparked, combined with the prince's edict, gave the Minamoto throughout the country a pretext for revolt, leading to uprisings by Minamoto no Yoritomo and Kiso no Yoshinaka. He is thus a pivotal figure whose actions set off the Genpei War. His death poem is celebrated: "The buried tree that bloomed not even once — how sad the end to which this body comes."

A seasoned warrior embodying both literary and martial excellence. Gifted in waka and skilled in arms, he navigated carefully under Taira rule for many years. But in his final years he showed the resolve to throw his aged body into the struggle for a just cause. His death poem, comparing his fate to a "buried tree that never bloomed," reveals a quiet sorrow at an unrewarded life alongside samurai pride.

By helping broadcast Prince Mochihito's edict throughout the country, he fired the opening shot of the Genpei War. Byōdōin in Uji is known as the place of his last stand. As a warrior who was also an accomplished poet, Yorimasa was handed down to later generations as an ideal of the dual cultivation of letters and arms. The legend of his slaying of the nue became material for Noh and Kabuki.