Antique Japanese Muromachi Katana Sword attributed to Kaifu with Inlaid Iron Sukashi Tsuba and Shakudō Figure Fuchi-Kashira - NBTHK Hozon

• Signature (Mei): Mumei (unsigned), attributed by the NBTHK to the Kaifu school 無銘（海部）
• Swordsmith: Kaifu school 海部 (NBTHK attribution; no individual smith named)
• School / Tradition: Kaifu 海部, Awa Province provincial tradition
• Period / Province: Muromachi period, koto, Awa Province (modern Tokushima, Shikoku). The NBTHK paper attributes the school; the period is the assessment of the previous Japanese dealer
• Certificate: NBTHK Hozon Token 保存刀剣 no. 3039165, issued 3 June 2026
• Japanese Registration (Tōroku-shō): Gunma no. 43028, issued 15 December 1987
• Mounting: Complete katana koshirae: black lacquer saya with fine gold flecks, iron sukashi tsuba with small inlays, shakudō nanako figure fuchi-kashira with gold highlights, black silk tsuka-ito
• Blade Length (Nagasa): 65.4 cm (2 shaku 1 sun 6 bu, just under, as recorded on the NBTHK certificate; 65.5 cm on the tōroku-shō)
• Curvature (Sori): 2.2 cm
• Mekugi-ana: 1
• Shape (Sugata): Shinogi-zukuri, iori-mune, chū-kissaki, a well-marked curvature for the length
• Jihada: Itame mixed with mokume, with flowing grain towards the shinogi; the grain stands out clearly
• Hamon: Narrow suguha base with gentle notare undulations, nioi-deki
• Habaki: Single-piece, silver-toned, with diagonal neko-gaki file marks

An unsigned katana of 65.4 cm, attributed by the NBTHK to the Kaifu school 海部 of Awa Province on Shikoku. The Hozon Token certificate was issued on 3 June 2026, so the attribution reflects the society's current judgement. The blade is registered in Japan and comes complete in a black lacquer koshirae.

The shape is a shinogi-zukuri katana with an iori-mune and a chū-kissaki. A curvature of 2.2 cm over 65.4 cm gives it a lively, well-marked bend. A blade of this length with this much curvature is typical of the uchigatana of the late Muromachi period, a sword worn edge-up through the belt and made to be drawn and used quickly.

The hamon is narrow and restrained: a suguha base that moves in gentle notare undulations, formed in nioi. This is not a showy temper line. Kaifu smiths were known above all for working blades, and the sober hamon matches that reputation.

The steel is the most interesting part to study. The jihada is an itame mixed with mokume, with grain that flows towards the shinogi, and it stands out clearly across the surface, a forging texture typical of provincial work. The polish is an older one, with light marks and visible grain in places. The tang keeps a tapered profile ending in a rounded kuri-jiri, with a single mekugi-ana, and it shows no sign of heavy shortening. Its dark, even patina has never been cleaned.

Koshirae Details

The tsuba is a round iron plate cut in openwork (sukashi) with spokes radiating out from the centre like a wheel. On the rim, a stream winds in low relief, and on one face a small chrysanthemum flower and a fan-shaped motif are inlaid in yellow metal. The reverse carries a second flower and a few tiny inlaid dots. The contrast between the austere iron openwork and these small bright accents is the charm of the piece.

The fuchi and kashira are a matching pair in shakudō on a fine nanako (fish-roe) ground, carved in relief with figures picked out in gold. On the kashira, two figures sit facing each other beneath a bamboo fence and leaves; on the fuchi, figures in gold and silver carry a long object across the band, with bamboo leaves and a fence behind them. Figure scenes on nanako ground were a classic subject of Edo-period metalworkers.

The tsuka is wrapped in black silk hineri-maki over white same, and the wrap is clean and tight. The menuki, in dark patinated metal with small gold accents, are figural pieces largely covered by the wrap. The saya is glossy black lacquer scattered with fine gold flecks, with black horn fittings and a dark grey sageo. The habaki is single-piece, silver-toned, filed with diagonal neko-gaki marks, and the two seppa are copper.

The Attribution: Kaifu 海部

The blade is unsigned, and the NBTHK attributes it to the Kaifu school as a whole, without naming an individual smith. That is the usual form for mumei Kaifu work: the school's style is recognisable, but its many smiths shared names and methods over several centuries, so a school attribution is the honest level of precision.

The best-known name in the school is Ujiyoshi 氏吉. Tradition places the first Ujiyoshi in the Ōei era (1394–1428), but Japanese dealers point out that signed work only appears from around the Meiō era (1492–1501), in the middle of the Muromachi period. The most famous Kaifu sword, the meibutsu Iwagiri Kaifu 岩切海部 ("the rock-cutting Kaifu"), is a katana signed by Ujiyoshi and is said to date from around the Eishō era (1504–1521). Other names recorded for the school include Yasuyoshi 泰吉, Yasumitsu and Yasunaga.

Kaifu blades are best known for the kataki-ri-ha form, a blade with a flat face on one side and a bevel on the other, often found on wakizashi. This katana, by contrast, is a conventional shinogi-zukuri fighting blade, and its attribution rests on the steel and the temper rather than on any unusual shape.

Kaifu: Swords of the Awa Coast

Kaifu is a coastal district in the south of Awa Province, modern Tokushima Prefecture on the island of Shikoku. Encouraged by the local Kaifu clan, smiths there produced swords from the medieval period until the end of the Edo period, and their work earned a reputation for robustness and cutting ability. Kaifu castle guarded Awa's border with Tosa, and when Chōsokabe Motochika of Tosa took it in the 1570s, the school declined.

It survived thanks to the Hachisuka family, who became lords of Awa (Tokushima domain) after 1585. Under their protection the Ujiyoshi family moved to the castle town of Tokushima and went on forging until the end of the Edo period, which makes Kaifu one of the longest-lived provincial traditions in Japan.

What is offered here is an unsigned Muromachi-period katana of 65.4 cm, attributed to the Kaifu school by an NBTHK Hozon certificate issued in June 2026, registered in Japan, and complete in a black lacquer koshirae with an inlaid iron sukashi tsuba and shakudō figure fuchi-kashira.