He was the third son of Yukichika UNNO who appeared in 'Hogen Monogatari' and 'Heike Monogatari' and was known as a master of archery who represented the early Kamakura period.
「保元物語」や「平家物語」などに登場する海野幸親の三男で、鎌倉時代初期を代表する弓の名手として知られる。