Blade for a Long Sword ("Tachi"), Named “Shishiō”

It is said the emperor gave this tachi sword to the Heian-period warrior Minamoto no Yorimasa to honor his slaying of a monster known as the Nue. The antique shape of the slim, deeply-curved blade is representative of the late Heian period. The hamon, or temper pattern created during the hardening process, exudes a beautiful simplicity with its narrow, straight shape. The hilt, sheath and metal fittings of the sword mounting are coated in black lacquer, with a dark blue braid wrapped around the sheath. This kind of black-lacquered mounting was commonly used by samurai warriors and is often depicted in picture scrolls.

These are thought to date back to the late Kamakura period, making them extremely valuable examples of pre-medieval Japanese swords and fittings. According to legend, the emperor awarded this blade to the samurai Minamoto no Yorimasa (1104–1180) for slaying a chimera-like monster known as the Nue. The blade’s slender form and pronounced curve are features of 12th-century samurai swords, which were designed for slashing attacks from horseback.

— Museum description: Tokyo National Museum (CC BY 4.0), via ColBase / Japan Search.