Tachi (inscribed Kunimune)

A Kamakura Blade in the Owari Tokugawa Collection

Two characters cut into the tang read "Kunimune." That signature, carved more than seven centuries ago, identifies one of only four swords by this smith to hold National Treasure status in Japan. The blade measures 80.1 centimeters along its cutting edge, curves 2.5 centimeters at its deepest point, and rests today in the Tokugawa Art Museum in Nagoya, where it arrived through one of the more interesting succession stories in Edo-period daimyo history.

The smith known as Bizen Saburo Kunimune worked in the mid-Kamakura period, roughly the thirteenth century. He belonged to the Naomune school of Bizen Province, in present-day Okayama Prefecture, a lineage separate from the dominant Osafune workshops of the region. Accounts of his parentage vary; some genealogies make him the third son of Naomune himself, others the third son of Naomune's son Kunizane. What the sources agree on is the nickname "Saburo," meaning third son, and a remarkable second act: tradition holds that he later moved east to Kamakura, reportedly at the invitation of the Hojo regents, and helped lay the groundwork for what became the Soshu tradition of swordmaking.

This particular tachi, a long sword worn edge-down and suspended from the belt, shows none of that later Kamakura austerity. It is pure Bizen work: a flamboyant choji-midare temper line, the pattern named for its resemblance to rows of clove buds, mixed with rounded gunome undulations and brightened by fine martensite crystals known as konie. The Agency for Cultural Affairs, in its official designation record, calls the blade the fullest expression of the style this smith did best.

Why It Was Designated a National Treasure

Japan's postwar cultural property system moves in two steps. This sword was first designated an Important Cultural Property on November 14, 1953, then elevated to National Treasure on March 20, 1954, under designation number 00143. The interval of four months tells you how quickly the appraisal committee reached its conclusion.

Several factors weighed in its favor. The blade carries an authentic two-character signature, which matters enormously for a smith whose name was used across two or three generations. The tang has been shortened, a process called suriage that many old tachi underwent when fighting styles changed, but only slightly, and the signature survived intact along with three peg holes that map the blade's successive remountings. Despite the shortening, the sword keeps its koshizori profile, the curvature concentrated near the hilt that marks Kamakura-period work, along with a medium point and a tight, small-grained itame forging pattern in the steel.

Provenance reinforced the case. According to the Tokugawa Art Museum, the second Owari lord, Tokugawa Mitsutomo, gave the sword to his second son Matsudaira Yoshiyuki, founder of the Takasu Matsudaira branch family. When Yoshiyuki's descendant Matsudaira Yoshiatsu was called back to head the main house in the first month of 1739, becoming Tokugawa Munekatsu, eighth lord of Owari, he brought the blade with him. It has remained with the family, and later with the foundation that succeeded it, ever since.

That unbroken chain of custody is rarer than it sounds. Many famous swords scattered after 1868, and more after 1945. This one never left.

What to Look For

Stand close to the case and follow the temper line from the hilt toward the point. The choji pattern does not repeat mechanically; clusters of clove-bud shapes give way to rounder gunome waves, with bright streaks called ashi running down toward the edge. In the flat of the blade above the temper line, look for midare-utsuri, a faint, cloudy reflection of the hamon that floats in the steel like a shadow. Utsuri is notoriously difficult to reproduce and is one of the signatures of fine Kamakura-period Bizen forging.

The point section rewards attention too. The boshi, the temper line as it turns through the tip, shows a slight irregularity before finishing in a small circle with brushed-off traces, a detail recorded in the official designation text.

One caveat for planning a visit: like most sword collections in Japan, the Tokugawa Art Museum rotates its displays to protect the objects, and no single blade is on view year-round. The museum holds eight National Treasure swords among more than a thousand blades and mountings, so the gallery devoted to arms is never empty, but if seeing this specific Kunimune matters to you, check the museum's exhibition schedule or contact the museum before traveling. Photography inside the exhibition rooms is, as a rule, not permitted.

The museum building itself, opened in 1935 on the site of an Owari Tokugawa residence at Ozone, is worth unhurried time. Its first gallery recreates the atmosphere of a daimyo's formal reception rooms, which puts a sword like this one back into the world it was made to inhabit: an object of ceremony and lineage as much as a weapon.

Around the Museum

The Tokugawa Art Museum sits in Nagoya's Higashi Ward, about a ten-minute walk from Ozone Station on the JR Chuo Line and the Meijo subway line, or a short ride on the Me-guru sightseeing loop bus from Nagoya Station. Adjacent to the museum is Tokugawaen, a strolling garden built around a pond, at its best in late November when the maples turn. The Hosa Library next door preserves the book collection of the Owari lords and mounts its own small exhibitions.

Fifteen minutes away by taxi or a subway ride via Sakae, Nagoya Castle displays the rebuilt Honmaru Palace, whose painted reception chambers complement the museum's daimyo furnishings. Sword enthusiasts can extend the theme at Atsuta Shrine in the city's south, home to a separate treasure hall with its own celebrated blade collection and one of the most venerated sword-related sites in Japan, as the shrine enshrines the legendary Kusanagi sword among its sacred objects.

Plan a half day for the museum and garden together. The museum café and the garden's restaurant both handle lunch comfortably.