Tachi Sword (inscribed with Nobufusa's Name)

A Heian-Period Tachi Signed by the Smith Nobufusa

The blade runs 76 centimeters along its cutting edge, carries a deep curve of 2.3 centimeters set low toward the hilt, and tapers from a base 2.8 centimeters wide to a slender point. Cut into the tang, near the back edge above the rivet hole, are three characters that read "Nobufusa saku," meaning "made by Nobufusa." That short inscription places the sword among the oldest signed works in the long history of Japanese swordmaking.

Nobufusa worked in Bizen Province, the area covering the southeastern part of present-day Okayama Prefecture and the region that produced more celebrated swordsmiths than any other in premodern Japan. His blades belong to the late Heian period, broadly the eleventh and twelfth centuries, when the curved single-edged sword worn slung from the waist, the tachi, was settling into the form that later generations would treat as classical. A tachi was carried edge-down by mounted warriors, and its shape differs from the katana of later centuries, which was worn edge-up thrust through the belt.

Why the Sword Is a National Treasure

Two early Bizen smiths are recorded under the name Nobufusa. One belonged to the Ko-Bizen, or "Old Bizen," group, the loose community of smiths active in the province before organized schools took shape; the other was an early figure in the Ichimonji school, which flourished from the late Heian into the Kamakura period. Scholars have not settled which of the two forged this blade. What specialists do agree on is that among surviving works carrying the Nobufusa signature, this one is the most archaic in feeling and the finest in workmanship.

The sword was first protected as an Important Cultural Property in 1931. In 1952, under the cultural property law enacted two years earlier, it was raised to National Treasure, the highest rank Japan grants to an artwork or historic object. The mounting that holds the blade is included in the same designation as an attached item: an itomaki-no-tachi koshirae, a formal tachi fitting whose hilt and scabbard are wrapped in silk cord and dressed with metalwork.

What to Look For in the Blade

The first thing to register is the silhouette. The curve sits low, close to the hand, and the blade flares wider at the base before narrowing toward the point, a quality swordsmiths call funbari. Slender, deeply curved, and weighted toward the hilt, it reads at a glance as a work of the Heian period rather than the broader, more aggressive blades of later eras.

Look closely at the steel and a faint cloudy reflection appears along the surface, shifting as the blade is turned under the light. This is midare-utsuri, an irregular shadow within the grain that early Bizen smiths coaxed from their steel and that later generations found almost impossible to reproduce. The forging shows a fine ko-itame, a dense wood-grain figure. Along the edge runs the hamon, the tempered border, here a small irregular ko-midare with frequent streaks of activity reaching into the cutting edge. Toward the point the pattern grows especially lively, and the temper at the tip itself is deep, with a suggestion of flame.

The tang repays attention too. It is ubu, meaning it has never been shortened, a rare survival for a blade this old, and it keeps its original kijimomo, or "pheasant-thigh," shape, narrowing in the manner named for the bird's leg. The file marks across it run straight. Because the tang is untouched, the smith's signature survives exactly where he cut it.

From a Warlord's Hand to a Castle Town

The blade owes its survival in part to a gift. Sakai Tadatsugu (1527 to 1596) ranked first among the men later remembered as the Four Guardians of the Tokugawa, the commanders closest to Tokugawa Ieyasu through the wars that ended in his rule over all Japan. Tadatsugu is said to have received this Nobufusa blade from Ieyasu in recognition of service in the field, by one account after the Komaki and Nagakute campaign of 1584.

The sword then passed down through the Sakai family across generations. From 1622 the Sakai held the Shonai domain in what is now coastal Yamagata, governing from Tsuruoka for more than two centuries until the end of the samurai era. The blade stayed with the family throughout. That it now rests in a museum far from the Bizen forges where it was made is a direct consequence: the Sakai themselves founded the institution that keeps it.

Visiting the Chido Museum and Tsuruoka

The Chido Museum stands on the western edge of the former Tsuruoka Castle grounds, on land that once held the Sakai family's official residence. The lords created it to hold their heirlooms and the region's history together in one place. Beyond the sword collection, the grounds gather several Meiji-era buildings moved here for preservation, among them a former district government office and an old police station with elegant Western-influenced facades, a steep thatched multi-story farmhouse brought from the mountain village of Tamugimata, and a garden behind the inner rooms that carries a national Place of Scenic Beauty designation.

One practical point matters for anyone hoping to see the Nobufusa blade itself. Like most fragile swords, it is not on permanent view and appears only during special exhibitions, often those devoted to the Sakai treasures. The museum holds a second National Treasure tachi as well, signed Sanemitsu, which the same Sakai Tadatsugu received from the warlord Oda Nobunaga. Checking the current exhibition schedule before a visit is wise.

Tsuruoka itself rewards a longer stay. The city sits near the three sacred mountains of Dewa, a major pilgrimage destination, and is known across Japan for its food culture. The museum is roughly ten minutes by bus from Tsuruoka Station toward Yunohama Onsen, getting off at the Chidohakubutsukan-mae stop, or about ten minutes by car from the Tsuruoka interchange.