Antique Japanese Katana Sword with Gold-Inlaid Iron Tsuba, Attributed to Chikuzen Nobukuni — NBTHK Hozon

• Signature (Mei): Mumei (無銘) - unsigned
• Attribution: Chikuzen Nobukuni (筑前信国) school, per NBTHK kantei
• Certificate: NBTHK Hozon Kanteishō No. 3037362 (Reiwa 7 / 2025)
• Type: Katana
• Period: Edo Period (Shintō)
• Mounting: Black urushi koshirae with gold-inlaid iron tsuba and crested (mon) fittings
• Blade Length (Nagasa): 69.4 cm (2 shaku 2 sun 8 bu kyō)
• Curvature (Sori): 1.2 cm
• Mekugi-ana: 3 (2 plugged) - suriage
• Shape: Shinogi-zukuri with iori-mune and chū-kissaki
• Jihada: Bright, tightly forged ko-itame
• Hamon: Suguha-chō with gentle notare, nioiguchi with ko-nie and ashi
• Boshi: Ko-maru

This Katana is a work of the Chikuzen Nobukuni school, attributed by the NBTHK in a current Hozon appraisal (Reiwa 7 / 2025). The blade is mumei and suriage - it was shortened at some point in its working life, and its three mekugi-ana (two now plugged) record that history. The original signature was lost in the shortening, which is why the attribution rests on the NBTHK's expert reading of the workmanship rather than on a surviving mei. This is the normal and respected basis on which shortened Edo blades are classified.

The sugata is a clean shinogi-zukuri with iori-mune, a balanced chū-kissaki, and a shallow, composed 1.2 cm sori over a 69.4 cm blade - the calm, purposeful profile of a Shintō-era katana. The blade is healthy and brightly polished.

The jihada is a tightly forged ko-itame, bright and well-packed - the disciplined, refined steel for which the Nobukuni lineage is known. The hamon runs as a suguha-chō with a gentle notare movement, worked in a soft nioiguchi with fine ko-nie and ashi entering the temper; the boshi turns back in a neat ko-maru. The result is a quietly classical blade in which the brightness of the steel and the evenness of the work carry the interest.

Koshirae Details

The blade is housed in a coordinated black koshirae. The saya is finished in glossy black urushi lacquer and dressed with a dark-blue-and-white sageo. The tsuba is a round iron plate with a distinctive twisted-rope (nawame) rim and gold zōgan (inlay) describing grasses and plant motifs across the surface, with one of the openings cut in the shape of a flower - a refined, scholarly piece of ironwork.

The grip fittings are notable for their kamon (family crests). The fuchi and kashira carry crests in relief - a cross-within-a-ring (the maru-ni-jūmonji form, borne among others by the Shimazu of Satsuma) and a floral roundel - and the gilt menuki beneath the wrap are themselves three-leaf crest roundels. Crests of this kind indicate that the mounting was made for a samurai family; we describe them as observed and make no documented claim of ownership by any specific clan.

The tsuka is wrapped in black silk ito over white same (rayskin) in the traditional hineri-maki diamond pattern, with a gilt habaki at the blade collar. The whole presents as a dignified, crested samurai mounting in good order.

The Chikuzen Nobukuni School

The Nobukuni name is one of the oldest and most respected in Japanese sword history. The line began in Kyoto (Yamashiro province) in the Nanbokuchō period, its founder traditionally counted as a pupil of the great Sōshū master Sadamune; the earliest Nobukuni blades show strong Sōshū-den character.

In 1602 (Keichō 7), the smith Nobukuni Yoshisada moved to Chikuzen province (today Fukuoka, in Kyūshū) at the invitation of the daimyō Kuroda Nagamasa, lord of the new Fukuoka domain. From that point the school served the Kuroda clan as retained smiths (kakae-kaji), generation after generation, through the Edo period and into early Meiji. Its smiths - Yoshisada, Yoshimasa, Yoshitsugu, Yoshikane, Shigekane and their successors - were known collectively as the "Tsukushi Nobukuni," one of the most prosperous swordmaking groups in all of Kyūshū. The school's most celebrated member, Shigekane, was summoned to Edo to forge for the eighth Shōgun Tokugawa Yoshimune and was granted the honour of carving the hollyhock (aoi) crest on his tangs.

Workmanship of the school blends the classical Yamashiro/Sōshū inheritance with the robust Kyūshū styles of the Shintō age: a bright, well-forged ko-itame jigane (often with flowing nagare and fine ji-nie), and hamon ranging from calm suguha to lively chōji- and gunome-midare. A blade attributed to this school is, in effect, a piece of that long and well-documented Kuroda-domain tradition.

About This Attribution

Because the blade is mumei and suriage, its name comes from kantei - the trained judgement of the NBTHK's appraisers - rather than from a signature. The fresh NBTHK Hozon paper (2025) confirms both the authenticity of the blade as a genuine antique nihonto and the school attribution to Chikuzen Nobukuni. For a collector this offers a documented, school-attributed Edo katana in attractive crested mounts, on the strength of a current paper from Japan's principal appraisal body.