Sanetsugu (真次) is a name borne by smiths across multiple lineages within the western Japanese swordmaking tradition. The most prominent is Sanetsugu of Province, working in the early period within a school traditionally said to have begun with Yasutsugu around the Jōan era. Representative smiths — Moritsugu, Tametsugu, Tsugie, Tsunetsugu, and others — share the character "tsugu" as a common element, and Sanetsugu continued for several generations from the Jōō era through the Ōei period. A separate Sanetsugu, possibly affiliated with the Yoshii line, was active around the Teiwa era of the period.
The style that Sanetsugu represents is characterized by conspicuous in the forging with a somewhat standing grain, producing what is often called a "-like" texture. Minute adheres thickly, with appearing and a faint arising. The is typically calm in a mode or mixed with , , and -like elements, with and ; gathers in clusters and adheres thickly, while and occur. Compared with contemporary works, the tends toward (subdued), giving an overall impression that is somewhat restrained and austere. The is typically with . A distinguishing structural feature, differing from , is that signatures are cut on the and tang file marks are in .
Sanetsugu's , bearing the distinctive signature and file marks, preserves an of high dignity with abundant and strongly arched curvature around the lower portion — a distinctive trait of the group. The has affirmed that every point displays the school's notable features, and that the blade remains in (sound and well-preserved) condition. His works are valued both for their fine workmanship and as precious documentary material for the tradition.