Former Nine Years' War participant Minamoto no Yoshiie
Background
While most provinces were overseen by just a Governor, Mutsu, in what is now the Tohoku region, had a military general in charge of controlling the Emishi natives, who had been subjugated when the Japanese took over the area in the ninth century. Historically, this post was always held by a member of the Abe clan, and there were many conflicts between the Abe general and the Governor over administrative control of the province.
In 1050, the general overseeing the Ainu was Abe no Yoritoki, who levied taxes and confiscated property on his own, rarely paying any heed to the wishes of the province's Governor. The Governor sent word to the capital in Kyoto asking for help, and as a result Minamoto no Yoriyoshi was appointed both Governor and commander-in-chief over controlling the natives. He was sent with his son Yoshiie, then age fifteen, to stop Abe.Legacy
Minamoto no Yoshiie is thus considered the founder of the Minamoto clan's great martial legacy, and is worshiped as a particularly special and powerful ancestor kami of the clan. As a kami and a legend, he is often called Hachimantarō, "Child of Hachiman, the god of war."
A famous renga from the Kokon Chomonjū was exchanged between Sadato and Yoshiie when Sadato was forced to flee his castle on the Koromo River.  Yoshiie said, Koromo no tate wa hokorobinikeri, Koromo Castle has been destroyed ("The warps of your robe have come undone"), to which Sadato replied, toshi o heshi ito no midare no kurushisa ni, "over the years its threads became tangled, and this pains me."