Active during the Tembun era (1532-1555), Yasuharu was one of the smiths working in the late Soshu tradition in the castle town of Odawara and under the jurisdiction of the Hojo clan. He was originally from Shimada, in Suruga Province, and went to Odawara in 1521 together with his teacher Shimada Yoshisuke Nobusada. In 1532 he was given the use of the character 'Yasu' replacing a different character reading 'Yasu'in his name by Hojo Ujiyasu, the lord of Odawara Castle. He taught a number of smiths at Odawara, including Yasuie, Yasukuni, Yasuhiro, Yasushige, and Terushige. A second generation signed with a similar signature.