Antique Japanese Tantō, Mumei, Attributed to Koyama Munetsugu (固山宗次) — Direct Attribution via Historic 1951 Cultural Properties Registration

A vivid, lively gunome-midare hamon over a clear, tight itame-hada, from a master famed for uniting supreme cutting power with refined artistic beauty

We are pleased to present an exceptional unsigned Shinshintō-era tantō, attributed directly to the legendary master Koyama Munetsugu (固山宗次) on its historic 1951 registration certificate. Officially designated in March 1951 (Shōwa 26) by the Cultural Properties Protection Committee (Bunkazai Hozon Iinkai, the predecessor to the modern Agency for Cultural Affairs) during Japan's famed early post-war "daimyō registration" period, this blade possesses extraordinary historical value and stands fully prepared for immediate appreciation.

On the smith — Koyama Munetsugu (固山宗次)

Koyama Munetsugu was one of the undisputed titan swordsmiths of the late Edo (Shinshintō) period. Renowned not only for his gorgeous, artistic Bizen-style swords, Munetsugu was obsessed with practical performance. He personally studied tameshigiri techniques and worked closely with the famous executioner and sword tester Yamada Asaemon to perfect his steel. His blades were celebrated for achieving a rare harmony of extraordinary cutting power (saidan-mei) and refined aesthetic beauty, earning him a reputation that rivaled or even surpassed the top master testers of his time.

Provenance and historical registration

This dagger carries a distinct historic provenance. It was registered in Tokyo in March 1951 by the Cultural Properties Protection Committee, and this early registration directly attributes the unsigned work to Koyama Munetsugu.

Export notice: As required by Japanese law, the original physical daimyō registration card must be surrendered to the Board of Education upon international export. However, a high-resolution copy can be provided with your order upon request (please leave a note during checkout).

Workmanship and condition

The blade is preserved in flawless, pristine condition, entirely free of nicks, rust, or chips. Fully polished to a fine sheen, the steel presents a clear, tight itame-hada (wood-grain pattern) filled with active, shimmering chikei (dark lines within the steel) and yubashiri (spilling nie). The hamon is a dynamic, irregular gunome-midare (irregular clove-shaped pattern), bounded by a vivid, sharply defined nioiguchi (temper-edge boundary). The bōshi (tip temper) enters with lively activity (midare-komi), completing a well-balanced and energetic temper line.

Form

A beautifully proportioned hira-zukuri tantō with no curvature (mu-sori, 0.0 cm). Measuring 19.7 cm in length, with a well-balanced thickness of 6.1 mm against a width of 22.5 mm, it offers a sleek, classical shape that highlights the high-level forging skill of the late Edo period.

The mounting (shirasaya)

The blade is housed in a shirasaya (plain wood resting scabbard).

A pristine Shinshintō tantō attributed to Koyama Munetsugu by Japan's official Cultural Properties Protection Committee during the historic 1951 registration. Boasting flawless health, vivid steel activity, and supreme historical pedigree, this is a truly unique addition to any high-caliber Japanese sword collection.

Specifications

• Type: Tantō (短刀), hira-zukuri with iori-mune; ubu, mumei (unsigned); Shinshintō era (late Edo period); mu-sori (no curvature)
• Smith: Attributed to Koyama Munetsugu (固山宗次)
• Signature (mei): Unsigned (mumei), ubu nakago
• Attribution: Historic 1951 (Shōwa 26) registration by the Cultural Properties Protection Committee (Bunkazai Hozon Iinkai), Tokyo, March 1951
• Jigane: Clear itame-hada with active chikei and yubashiri
• Hamon: Irregular, lively gunome-midare with a clear, tight nioiguchi
• Length of edge (nagasa): 19.7 cm (approx. 7.76 in / approx. 6 sun 5 bu)
• Curvature (sori): 0.0 cm (mu-sori)
• Width at base (motohaba): 22.5 mm (approx. 0.89 in)
• Thickness at base (motokasane): 6.1 mm (approx. 0.24 in)
• Peg holes (mekugi-ana): 1
• Weight (blade only): 120 g
• Condition: Excellent; freshly polished, completely free of rust, chips, or flaws
• Mounting: Shirasaya
• Registration No.: Tokyo No. 22685 (東京 第22685号)