Sword (Unsigned Sadamune (famous Tortoiseshell Sadamune))

A Shogun's Sword That Carries No Signature

The blade known as the Kikkō Sadamune bears no smith's name on its tang, yet it has been credited to the swordsmith Sadamune for centuries. It is a National Treasure of Japan, kept today at the Tokyo National Museum in Ueno. The cutting edge measures 70.9 centimeters, with a gentle curvature of 2.4 centimeters and a narrow, balanced point.

Its informal name comes from a small carving on the tang: a tortoiseshell pattern enclosing a flower, in Japanese a kikkō motif. That engraving was added after the blade had already been cut down to its present length, and over time it became the sword's identifying mark.

The weapon began as a longer tachi, a sword slung edge-down from the belt in the manner of the Kamakura period. At some point it was shortened, a process called ōsuriage, and remounted as a katana worn edge-up. The reshaping removed whatever signature the original tang may once have held, which is one reason the attribution rests on style rather than an inscription.

Sadamune and the Sōshū Tradition

Sadamune, known by the common name Hikoshirō, worked in Sagami Province around the early fourteenth century, as the Kamakura period gave way to the Nanbokuchō era. By tradition he was the son, or perhaps the adopted son, of Masamune, the smith usually regarded as the figure who perfected the Sōshū tradition of forging. Later generations counted Sadamune among the "Ten Disciples of Masamune," a group of leading smiths said to have carried that tradition across Japan.

One peculiarity defines his legacy. No blade survives that carries Sadamune's own signature, so every work given to his hand is an attribution made by connoisseurs. Edo-period appraisers nonetheless ranked him very highly, placing him beside Masamune, Yoshihiro, and Yoshimitsu as one of the four supreme makers. His steel, prized for a clear bluish-black grain, came to be called "Sadamune-hada," the Sadamune skin.

Set against Masamune, whose blades can look dramatic, Sadamune's work is quieter and more even in temper. Three swords attributed to him hold National Treasure status, and the Kikkō Sadamune is counted among the most refined of them.

Why It Was Designated a National Treasure

The Agency for Cultural Affairs describes this katana as a representative example of Sadamune's calm and dignified manner, and notes that its state of preservation rivals that of the three short blades by the same smith already listed as National Treasures. Soundness matters a great deal with old swords, since centuries of polishing and corrosion thin and alter a blade. A piece that retains its proper proportions and a healthy surface is rare.

The sword also appears in the Kyōhō Meibutsu-chō, a catalogue of celebrated blades compiled in the early eighteenth century at the order of the shogun Tokugawa Yoshimune, who had the appraising Hon'ami family record the finest swords of the realm. Inclusion in that register placed the Kikkō Sadamune among the named treasures of the age.

It was first protected as an Old National Treasure in 1936, while in the keeping of the Tokugawa main house, and received its present designation under the postwar Law for the Protection of Cultural Properties on 29 May 1965.

What to Look For

The tortoiseshell-and-flower carving on the tang is the detail that gives the sword its name, and it sits on the reverse side, the face turned toward the wearer's body. Because it was cut after the blade was shortened, it points to a later owner's wish to mark a sword that had lost its original signature.

Along the edge runs a temper line based on a shallow, undulating notare with scattered irregularity, the kind of subdued pattern that earned Sadamune comparison with his teacher. The body is forged in shinogi-zukuri, with a ridged back of the iori, or gable, form, and the point is of medium length. The blade width is slightly narrow, which lends the whole a restrained silhouette rather than a flamboyant one.

Seen together, the shortened tang, the added crest, and the temper of the steel record both the craftsmanship of the early fourteenth century and the later hands through which the sword passed.

The Sword's Journey to Ueno

The recorded ownership reads like a map of Edo-period power. Early accounts place the blade with Matsudaira Naomasa, a grandson of Tokugawa Ieyasu and lord of Matsue, after which it moved through the Hijikata and Nanbu houses. The Owari branch of the Tokugawa later acquired it, and in 1698 presented it to the fifth shogun, Tokugawa Tsunayoshi, during his formal visit to the Owari residence. From then it ranked among the heirlooms of the Tokugawa main house.

In the twentieth century the sword left Tokugawa hands, passing to the industrialist Nakajima Kiyoichi and later to the collector Watanabe Seiichirō. In 1991 Watanabe gave it to the Tokyo National Museum, where it remains today.

Visiting and the Ueno Area

The Tokyo National Museum stands at the northern end of Ueno Park, a short walk from Ueno Station. Japanese swords are shown in the Honkan, the main gallery building, in the room devoted to arms and armour. Blades are rotated for conservation reasons, so the Kikkō Sadamune is not on permanent view. Anyone hoping to see this particular sword should check the museum's exhibition schedule before traveling.

Ueno Park rewards a longer stay. Within walking distance are the National Museum of Western Art, the National Museum of Nature and Science, Ueno Zoo, and the precincts of Kan'eiji, the temple once tied to the Tokugawa family whose patronage runs through this sword's own story.