Sword (gold Inlay Inscription Dated December 13th of Tensho

Inaba Go: The Phantom Blade of a Legendary Swordsmith, Now on View in Iwakuni

Among the small circle of swords treasured as the finest works of Japanese steel, very few carry a mystique quite like that of the Inaba Go (稲葉江). Forged in the fourteenth century by the elusive master Gō Yoshihiro, passed from a Warring States retainer to Tokugawa Ieyasu himself, and then handed down through several of early modern Japan's most powerful families, this single blade tells a story that traverses six centuries of Japanese history. Designated a National Treasure of Japan, the Inaba Go is today kept by the Kashiwabara Art Museum in the castle town of Iwakuni, Yamaguchi Prefecture, where visitors can see it during scheduled special exhibitions.

A Sword Few Have Ever Seen

The smith behind the Inaba Go is Gō Yoshihiro (also written Gō no Yoshihiro), believed to have worked in Matsukura, in the province of Etchū, around the area of present-day Uozu City, Toyama Prefecture. He is traditionally counted among the so-called Masamune Jittetsu, the ten greatest disciples of the Sōshū master Masamune, and he is often placed at the head of that group. Yet despite his lofty reputation, Yoshihiro is said to have died young, and he left almost no signed work behind.

Because of this scarcity, a saying has circulated among sword enthusiasts for centuries: "No one has ever seen Gō, nor a ghost." Only eleven blades authenticated as Yoshihiro's work by the Honami family of sword appraisers are known to survive. Of these, the Inaba Go and the Toda Go (held by the Maeda Ikutokukai and also a National Treasure) are considered the two finest. Standing in the same room as the Inaba Go, then, is a rare encounter with a master whose hand shaped very few of the swords that survive today.

From Mino Warlord to Tokugawa Shogun: The Blade's Journey

Inaba Shigemichi and the Gold-Inlaid Inscription

The blade takes its name from Inaba Kan'uemon-no-jō Shigemichi, son of Inaba Yoshimichi (better known as Ittetsu), one of the three senior retainers of western Mino who served the Saitō and later the Oda clans. In the twelfth month of 1585 (Tenshō 13), Shigemichi commissioned the ninth-generation Honami master, Kōtoku, to shorten the sword and authenticate it. The result is a gold-inlaid inscription in the tang: on one side, "Tenshō 13, 12th month, Gō, shortened by Honami" with Kōtoku's floral signature; on the other, "Owned by Inaba Kan'uemon-no-jō."

Acquired by Tokugawa Ieyasu

Not long after, Tokugawa Ieyasu took a personal interest in the blade and acquired it for the modest sum of five hundred kan. In the autumn of 1600, as the Battle of Sekigahara approached, Ieyasu marched east to subdue Uesugi Kagekatsu before turning back to confront Ishida Mitsunari in the heartland. Leaving his second son Yūki Hideyasu at Utsunomiya to hold the Uesugi front, Ieyasu is said to have presented Hideyasu with his personal armor, his war baton, and this very sword as a gesture of encouragement.

A Daimyo Heirloom Across Three Centuries

After Sekigahara, Hideyasu received the domain of Echizen-Kitanoshō (today's Fukui), and the sword passed to him. From there it was inherited by his descendants, entering the Matsudaira family of Tsuyama through his grandson Mitsunaga's adopted son Nobutomi. The Tsuyama Matsudaira kept the blade until after the Second World War. It then moved through several private hands until 2019, when Kashiwabara Corporation, based in Iwakuni, purchased it and donated it to the museum now known as the Kashiwabara Art Museum, returning the phantom sword to public view.

Why the Inaba Go Was Designated a National Treasure

The Inaba Go was first designated an Important Art Object in 1933, listed as an Old National Treasure in 1936, and then re-designated a National Treasure under the current Law for the Protection of Cultural Properties on 9 June 1951. The reasons given by the Agency for Cultural Affairs speak to both its artistic quality and its documented pedigree.

Technically, the blade represents the pinnacle of Yoshihiro's art. Its forging pattern is a finely packed small wood-grain (ko-itame), with a thick, evenly distributed ji-nie that sparkles like silver sand across the surface. The temper line moves with a gentle notare undulation mixed with regular gunome beats, deep in nioi and well adorned with ko-nie, with occasional streams of sunagashi. In the upper half above the monouchi, the temper broadens dramatically into a larger pattern, and the tip forms an almost continuous field of hardened steel. A single deep, confidently carved groove runs along the body, adding to the sword's commanding presence.

Its provenance is equally significant. The Inaba Go is recorded in the Umetada Oshigata, a famous seventeenth-century collection of sword rubbings, and later in the Kyōhō Meibutsu Chō, the official register of celebrated swords compiled on the orders of the eighth Tokugawa shogun Yoshimune. Few Japanese swords combine such depth of artistry with such a traceable and illustrious chain of ownership.

What to Look For When You Visit

The Silhouette of a Shortened Tachi

The Inaba Go was originally forged as a long tachi, a cavalry sword meant to be worn edge down. When shortened in 1585, much of the original tang was cut away, but the bold proportions were preserved: the blade still carries an ample width, a thick body, and a notably extended tip (kissaki). The result is a sword with the agility of a katana and the presence of a tachi — a silhouette that conveys both authority and grace.

The Brightness of Gō's Steel

Connoisseurs have long described Yoshihiro's work as "bright and clear in both ji and ha." Under the museum's lighting, look for the way the ji-hada seems to glow softly from within, while the temper line traces a crisp, luminous pattern along the cutting edge. This is the quality that earned Yoshihiro his reputation as Masamune's foremost heir.

The Golden Signature in the Tang

One of the blade's most historically significant features is the gold-inlaid inscription in the tang, carrying Kōtoku's authentication and naming its sixteenth-century owner. Reading these characters in person offers a direct link to the moment the sword entered recorded history — and to the hand of one of the most famous sword appraisers of the Tenshō era.

Visitor Information

The Kashiwabara Art Museum sits directly in front of the base station for the Iwakuni Castle Ropeway, in the historic Yokoyama district beneath the castle mountain. The museum houses roughly six thousand items of Japanese traditional art, including some eighteen nationally or regionally designated cultural properties. Because the Inaba Go is a fragile and priceless object, it is not on permanent display; visitors who wish to see it are encouraged to confirm scheduled special exhibitions before travelling.

Iwakuni is easily reached from Hiroshima by local train (about fifty minutes) or by limited express, and Iwakuni–Kintaikyo Airport connects the city directly with Tokyo. From JR Iwakuni Station or Shin-Iwakuni Station, regular buses run to the Kintai Bridge area, and the museum is a short walk from the bridge's western end.

Around the Museum

Kintai Bridge

Just across the Nishiki River from the museum stands the Kintai Bridge, an Edo-period wooden arched bridge first built in 1673. Its five graceful spans have become one of the most recognised landmarks of western Japan, and walking across it gives a vivid sense of the castle-town geography the Inaba Go entered when it came to Iwakuni.

Iwakuni Castle

A short ropeway ride above the museum leads to Iwakuni Castle, originally built in 1608 and reconstructed in 1962. From the keep, visitors can see the Seto Inland Sea, the Nishiki River, and the town laid out below — a view that helps place the samurai culture represented in the museum's collection in its landscape.

Kikkawa Historical Museum and the White Snake Museum

Also within walking distance are the Kikkawa Historical Museum, which preserves artefacts of the Kikkawa lords who governed Iwakuni, and the Shirohebi no Yakata (White Snake Museum), home to the pure-white Japanese rat snakes that have been revered as messengers of the goddess Benzaiten in Iwakuni for centuries.