Tantō Signed Bishū Osafune-jū Nagashige

The Tanto Signed Bishū Osafune-jū Nagashige is a National Treasure forged by Nagashige, a swordsmith of the Chōgi lineage within the Bizen Osafune school, dated to Kenmu 1 (1334, the year kōjutsu) during the Nanbokuchō period. The blade measures 26.0 cm in length with a motohaba of 2.5 cm. It strongly reflects Sōshū-tradition techniques, and its refined steel and temper have led it to be praised as a masterpiece displaying the finest craftsmanship of the Sōshū school. Tradition holds that the blade served as a reference piece (sashiryō) for Honami Kōtoku, the founding master of the Honami family of sword appraisers who served Toyotomi Hideyoshi. Its accompanying mounting dates to the early Edo period, suggesting the blade has been carefully preserved across the centuries. It received National Treasure designation on November 14, 1953, and remains in private hands today. As a Chōgi-school work that nonetheless shows pronounced Sōshū influence within Nanbokuchō-era Bizen swordsmithing, it is also valued as evidence of cross-fertilization between the Bizen and Sōshū traditions.