Antique Japanese Yoroidōshi Tantō, signed "Unju Fujiwara Nobukazu" (運寿藤原信一作), dated Keiō 3 (1867) — NBTHK Hozon Tōken, in a period kizami-saya mounting

An ubu, signed armor-piercing tantō of massive thickness by the Bakumatsu master Nobukazu of Tanba — u-no-kubi-zukuri form, with a spirited gold boar menuki and a matching kozuka

A rare, signed (zaimei) yoroidōshi (armor-piercing tantō) with an unshortened (ubu) tang has arrived, by the master smith Unju Fujiwara Nobukazu (運寿藤原信一), who worked in Tanba Province, dated the first year… [Keiō 3, 1867]. It carries the NBTHK (Nihon Bijutsu Tōken Hozon Kyōkai) "Hozon Tōken" certification, and is housed in a full period mounting — a characterful kizami-saya (ribbed scabbard) fitted with a lively gold boar (inoshishi) de-menuki. It is a solid, authentic piece from end to end.

Workmanship and condition

The blade has been given a fine polish and is in superb condition in both steel and temper. One small area of thin black rust, about 1 cm across, is found roughly 6 cm above the mune-machi (back notch); it does not significantly detract from appreciation, and reads instead as a touch of honest age. The jigane is a finely and densely packed ko-itame (small wood-grain) covered with fine ji-nie, giving a very clear, crisp texture. The temper line is based on a dignified, straight suguha, mixed with a very shallow notare and delicate ko-midare, the temper edge covered with fine, even nie that glows brightly. Rather than relying on flamboyance, it captivates through the quality of the forging and the clarity of the edge — a work full of the refinement one expects of a fine Bakumatsu smith.

Form

This is a robust yoroidōshi (armor-piercer) design, built with an extremely thick kasane of about 9 mm against a base width of only 26.2 mm. It is further shaped in u-no-kubi-zukuri — the back (mune) side pared down from the middle of the blade toward the tip — and carries a graceful saki-zori (curvature toward the point). The combination gives it the overwhelming solidity and sharp, purposeful stance of a custom-forged (chūmon-uchi) blade, uniting massive thickness with a keen, elegant silhouette.

On the smith — Unju Fujiwara Nobukazu (運寿藤原信一)

Nobukazu was a master smith celebrated for his outstanding forging skill in Bakumatsu-period Tanba Province (present-day central Kyoto / eastern Hyōgo). He was a pupil of Ishidō Unju Koreichi. The tang bears a clear date of "Keiō 3" (1867), conveying that this is a practical yet highly artistic work made against the turbulent backdrop of the closing years of the Edo period.

The mounting (koshirae)

The blade comes in a full period mounting: a characterful kizami-saya (finely ribbed/carved scabbard) fitted with a spirited gold boar de-menuki. A matching kozuka (small utility-knife handle) is also included, and the overall state of preservation is very good. The pairing of a solid, functional blade with a chic, refined ribbed mounting heightens its appeal as a collector's piece.

A powerful u-no-kubi-zukuri form with a 9 mm thickness and a beautiful saki-zori, an ubu signature bearing the Bakumatsu date of Keiō 3, a period mounting set off by its boar menuki, and NBTHK Hozon certification — a flawless piece in every respect, and a must-see for enthusiasts and collectors alike.

Specifications

• Type: Tantō (短刀) — yoroidōshi (armor-piercer), u-no-kubi-zukuri; ubu, zaimei
• Smith: Unju Fujiwara Nobukazu (運寿藤原信一), Tanba Province; pupil of Ishidō Unju Koreichi
• Signature (mei): "Unju Fujiwara Nobukazu saku" (運寿藤原信一作); dated "Keiō sannen hachigatsu-hi" (慶応三年八月日 / a day in the 8th month of Keiō 3, 1867)
• Jigane: Finely packed ko-itame with ji-nie, very clear
• Hamon: Suguha-based with shallow notare and delicate ko-midare; fine, even, bright nie
• Length of edge (nagasa): approx. 20.3 cm (approx. 7.99 in / 6 sun 7 bu)
• Curvature (sori): Saki-zori (curved toward the tip)
• Width at base (motohaba): 26.2 mm (approx. 1.03 in)
• Thickness at base (motokasane): 8.9 mm (approx. 0.35 in) — exceptionally thick
• Weight (blade only): 190 g
• Weight (blade in mounting, without scabbard): 360 g
• Condition: Finely polished; one small (~1 cm) thin black-rust spot about 6 cm above the mune-machi, otherwise excellent
• Mounting (koshirae): Period kizami-saya with gold boar (inoshishi) de-menuki; matching kozuka included
• Certification: NBTHK Hozon Tōken
• Registration No.: Saitama No. 7011 (埼玉 第7011号)