A fine Shinto blade by Echigo no Kami Sadatsune (越後守貞常), a swordsmith active in the late 17th century during the early Edo period. Another known example by the same smith bears the date inscription Tenwa 2 (1682), providing a useful reference for placing his work in the latter half of the 17th century. This blade measures 67.6 cm in nagasa with a sori of 1.0 cm and has been shortened by suriage at some point in its history. It is forged from Namban-tetsu (南蛮鉄), imported foreign steel that was brought into Japan through overseas trade and was particularly valued and used by swordsmiths during the early Shinto period. The use of Namban-tetsu is an especially interesting feature, reflecting the international trade and technological exchange of the early Edo period.
The blade has a fine ko-itame jihada and a clearly visible wavy hamon with pronounced nioi activity, giving it an attractive and lively appearance. It is preserved in a Japanese Imperial Navy naval sword mounting, complete with a traditional samegawa-covered scabbard, creating an appealing combination of an Edo-period Shinto blade and a historically significant military mounting.