Kaneuji, widely known as Saburo, is said originally to have been a Yamato smith of the line who signed with the name Kanetsugu. After studying under Masamune of , he moved to in Province, changed the first character of his name, and signed thereafter as Kaneuji. Among the "Ten Great Disciples of Masamune" (Masamune Jittetsu), his work is considered the closest to his master's own style, yet his individuality lies precisely in the point where elements of the Yamato tradition are blended with a -derived flavor. The first and second generations are distinguished on the basis of signature style: bold, large, angular characters are treated as first generation, while small signatures cut with a fine chisel are treated as second.
By incorporating elements into the Yamato tradition, Kaneuji founded a distinctive style characterized by small mixed with and pointed elements, a well-'d and that appear bright and clear, and active and . The varies from well-forged that becomes toward the edge, to compact with slight standing grain showing . The typically enters in with , turning back in . Apart from the Masamune-line smiths, there also existed in the period Yamato smiths who continued using the earlier signature Kanetsugu and whose works, referred to as Yamato , differ from the purely -school manner in incorporating elements of tradition.
Works attributed to the line display a character in both and , with notably bright and clear . Their signed pieces, though rare, provide valuable material for distinguishing generations within this complex lineage.