Yamana was born the son of Nitta Yoshishige.[1][2] His family descended from the Seiwa Genji lineage of the Minamoto clan.[2]
He lived in Yamana township in Kōzuke Province (present-day Yamana, Takazaki, Gunma Prefecture), taking the surname "Yamana", thus establishing the Yamana clan.[1][2]
On September 24, 1185, Yamana was appointed Governor (kami) of Izu Province.[3]
He served shogun Minamoto no Yoritomo, and participated in the Genpei War (1180-1185) and the Battle of Ōshū (1189) under his command.[1]
After the Revenge of the Soga Brothers incident in June 1193, Yamana was among the retainers present during the questioning of Soga Tokimune, one of the perpetrators of the incident.[4]
In 1195, Yamana accompanied Yoritomo on his visit to the Imperial Palace in Kyoto.[1]
Yamana died in February 1219.[1]