Tachi (inscribed Masatsune)

A Two-Character Signature on a Mountaintop

Near the base of the blade, on the side that faced outward when the sword hung at a warrior's hip, two large characters have been cut with a heavy chisel: Sanetsune. That signature, carved roughly nine centuries ago by a smith in Bizen Province, now rests inside a museum on Kunozan, a 216-meter mountain overlooking Suruga Bay in Shizuoka City. The sword it identifies, the Tachi Signed Sanetsune, was designated a National Treasure of Japan in 1951, and the museum that keeps it calls it the yokozuna of National Treasure tachi, borrowing the title reserved for sumo's grand champions.

The blade measures 89.4 centimeters along its cutting edge, with a deep curvature of 3.9 centimeters concentrated near the hilt. In an era when most tachi were slimmer and shorter, this one approached three shaku, the traditional unit marking an exceptionally long sword. It is broad, thick, and heavy in hand, a presence more than a weapon.

What the Sword Is

A tachi is the older form of the Japanese long sword, worn edge-down and slung from the belt, the standard sidearm of mounted warriors before the katana took over in later centuries. This one was forged in the late Heian period, most likely in the twelfth century, in Bizen Province, the region of present-day Okayama Prefecture that became the most prolific sword-producing center in Japanese history.

Its maker, Sanetsune, is traditionally counted among the Ko-Bizen smiths, the earliest identifiable school of the province. Documentary evidence about the man himself is thin, and his dates are not firmly established, so the attribution rests on the signature and the workmanship rather than on written records. What survives of his output is small. That scarcity, combined with the sheer scale of this blade, places the sword among the rarest works of its lineage.

The construction is shinogi-zukuri, the ridged cross-section that became the standard for Japanese long swords, with a peaked back edge. The point is compact and rounded in the style called ikubi, or boar's neck. The steel surface shows a tightly packed ko-itame grain, like fine wood figuring, dusted with minute crystalline particles known as ji-nie. Along the tempered edge runs a hamon of small irregular waves rich in activity, shifting to a gentle clove-like pattern toward the upper section. The tang has never been shortened. It keeps its original shape, three peg holes, and that bold two-character signature.

Why It Became a National Treasure

The sword received national protection early. It was designated an Important Cultural Property in September 1912, within the first generation of Japan's modern heritage system, and was elevated to National Treasure status on June 9, 1951, under the current Law for the Protection of Cultural Properties. Its registration number, 23, signals how quickly the postwar committee acted on it.

The official designation record explains the judgment. Grand, broad-bodied tachi of this type represent one distinct current within late Heian sword making, and the Sanetsune stands alongside the celebrated O-Kanehira and the Important Cultural Property blade by Toshitsune as a defining example of that current. Most Heian tachi are elegant and slender; a small number, made perhaps for presentation or for warriors of unusual stature, were forged on a heroic scale. Fewer still survive intact, unshortened, with their signatures in place.

The designation also covers the sword's mounting, an itomaki-tachi koshirae of the formal type used for shrine dedications. Its scabbard is finished in gold nashiji lacquer scattered with paulownia crests in maki-e, and the metal fittings are of shakudo alloy worked in a fine fish-roe ground with gilded paulownia crests throughout. The paulownia was a crest the Toyotomi family had used and the Tokugawa continued to deploy on formal occasions, and its repetition across scabbard and fittings marks this as a gift of state.

The Shogun's First Offering

Tokugawa Ieyasu, the founder of the Edo shogunate, died at Sunpu Castle in 1616 and was buried, by his own instruction, on Kunozan. His son and successor Hidetada ordered a shrine built over the grave, and the master carpenter Nakai Masakiyo completed the lavish complex in a year and seven months. In December 1617, when the enshrinement was carried out, Hidetada presented this tachi to the new sanctuary.

It was the first sword ever dedicated to Kunozan Toshogu. Over the following two and a half centuries, successive shoguns added their own offerings, and the shrine's collection of dedicated blades grew to around forty. The Sanetsune remained the senior piece among them, a Heian masterwork chosen by the second shogun to honor the first.

Why Hidetada selected a four-hundred-year-old Bizen blade rather than a contemporary one is not recorded. The choice speaks for itself. A sword already ancient in 1617, of a size and quality almost without parallel, was the appropriate measure of the man being deified as Tosho Daigongen, the Great Avatar Shining over the East.

Seeing the Blade, and What Surrounds It

The sword belongs to the Kunozan Toshogu Museum, which stands within the shrine precincts beside the shrine office. The museum holds more than two thousand objects, centered on items handed down within the shrine itself: arms and armor of the Tokugawa shoguns, personal effects of Ieyasu including his clocks and writing implements, and the famous Shida armor he wore in the Sekigahara campaign.

One practical point matters for planning. The Sanetsune is not on permanent view. The museum rotates its displays and brings the sword out for special exhibitions, which it announces on its exhibition page. Past showings have marked occasions such as the New Year season and the imperial accession. Anyone traveling specifically for this blade should check the current exhibition schedule before setting out. Even when the tachi itself is resting, the museum's rotating selection of shogunal swords and armor rewards the visit, and its National Treasure mounting has appeared in displays in its own right.

Reaching the shrine is half the experience. No road climbs Kunozan. Visitors either ride the Nihondaira Ropeway, a five-minute crossing from the Nihondaira plateau that skims a ravine with Suruga Bay spread below, or climb the 1,159 stone steps that zigzag up from the coastal side through old strawberry terraces. The steps take about thirty minutes at a steady pace and open onto wider and wider views of the bay with every switchback. The shrine and museum are open year-round from 9:00, with final museum entry at 16:45; admission to the shrine buildings and the museum is charged separately, and a combined ticket is sold.

Around Kunozan

The Nihondaira plateau at the ropeway's upper end is itself a designated Place of Scenic Beauty, with a 360-degree observation terrace that takes in Mount Fuji across the bay on clear days. The Nihondaira Yume Terrace, a viewing facility designed by architect Kengo Kuma, stands a short walk from the ropeway station.

Along the shore at the mountain's foot, the Kuno coast is lined with greenhouse strawberry farms. The stone-wall cultivation method developed here in the Meiji era turned the steep, sun-soaked slope into one of Japan's best-known strawberry districts, and from roughly December through May the farms offer picking sessions. Across the water, the pine grove of Miho no Matsubara, part of the Mount Fuji World Heritage inscription, is about thirty minutes away by car.

The shrine buildings themselves deserve unhurried time. The main sanctuary, a riot of carving and lacquer completed in 1617, is a National Treasure of architecture and the prototype for the grander Toshogu later raised at Nikko. Ieyasu's actual tomb stands behind it, up a final flight of steps, facing west toward his birthplace.