Antique Japanese Yoroidōshi (armor-piercing tanto), signed Yoshimitsu (吉光) — attributed to Tosa Yoshimitsu, late Muromachi period (Bunmei era) — an exceptionally thick hira-zukuri blade — in a period aikuchi koshirae with kage-maki-e saya and kozuka

Signed hira-zukuri yoroidōshi attributed to Tosa Yoshimitsu · a massive kasane of some 9 mm · well-forged itame-with-mokume · tight suguha with a deep turnback · in a characterful de-menuki aikuchi mounting with marbled kage-maki-e lacquer and a fitted kozuka

A most compelling and robust blade judged to be the work of Yoshimitsu, a master representative of Tosa province in the late Muromachi period. This is a hira-zukuri yoroidōshi (armor-piercing dagger) thought to have been forged around the Bunmei era of the late Muromachi period. Accompanied by a finely preserved period mounting, it unites the overwhelming strength of a practical fighting blade with a stirring historical value.

Workmanship and condition

The blade is very well polished and well preserved — remarkably sound and, for an old sword (kotō), essentially free of flaws overall. The one regret is a very small edge nick (ha-kobore) about 6 cm up from the ha-machi; this speaks to the blade's long history and in no way diminishes the fine appreciation value or the soundness of the piece as a whole. The jigane is an itame partly mixed with mokume, well forged so that the layers of the forging stand out clearly. The hamon is a suguha with a tight nioiguchi, turning back broadly at the point (bōshi). The tang (nakago) is firmly cut with the two-character signature Yoshimitsu. The mounting is a de-menuki-style aikuchi with a shadow-maki-e (kage-maki-e) lacquered scabbard; a distinctive fitting detail, in which one side of a peg-hole is left unpierced, preserves the character of the period to this day.

Form

The greatest feature of this piece is its astonishing thickness — a kasane of some 9 mm that overturns the ordinary idea of a tanto — in a commanding yoroidōshi form. The trim, ridgeless hira-zukuri body, together with a mune that draws a steep, deep line, radiates an extreme, purposeful beauty honed for one thing only: to pierce an opponent's armor and its gaps. The solid heft and taut tension felt the moment it is taken in hand convey directly the spirit of the samurai who threw himself, body and soul, into battle. This is precisely the refined mass and balance of a chūmon-uchi — a blade commissioned from a master smith by a warrior with a special purpose in mind.

On the smith — Tosa Yoshimitsu

Yoshimitsu was a master smith active in Tosa province (present-day Kōchi) around the Bunmei era (later 15th century) of the late Muromachi period. Tosa Yoshimitsu left many fine, highly practical blades, showing particular skill in carefully made works such as the yoroidōshi prized by samurai for self-defense and real combat. In an age awash with mass-produced blades, a chūmon-uchi like this — with an extra-thick kasane and excellent ground and edge — is exceedingly precious, and is very highly regarded in the appreciation and collecting of swords today.

The koshirae

The blade is accompanied by a well-preserved de-menuki aikuchi koshirae with a shadow-maki-e scabbard and a fitted kozuka. The hilt is a lavish full ray-skin wrap (sō-same-maki) — a mark of high-grade mountings — set with a splendid large central nodule (oyatsubu) as an accent. Boldly three-dimensional de-menuki in the form of an ox lend a refined design touch within the martial austerity. The saya is finished in a deep, flavorful marbled kage-maki-e of intermingled red and green, harmonizing beautifully with the menuki for an air of exceptional elegance. A kozuka is securely housed in the side of the scabbard, conveying the refinement of the samurai of the age and the high completeness of the ensemble as a set of tools.

An extremely powerful yoroidōshi by Yoshimitsu, entrusted with a samurai's life in the turbulent years on the eve of the Sengoku age. With its overwhelming thickness, clear ground and edge, and a high-toned aikuchi koshirae full of period feeling, it is an ultimate piece through which one can fully savor the essence of a practical fighting blade and the breath of history.

Specifications

• Type: Tanto — yoroidōshi (armor-piercing dagger), hira-zukuri
• Signature (mei): Yoshimitsu (吉光), two-character signature
• Certification: none (attributed to Tosa Yoshimitsu)
• Period: Late Muromachi period, ca. Bunmei era (later 15th century)
• Smith / province: Yoshimitsu — Tosa province (present-day Kōchi)
• Jigane: well-forged itame mixed with mokume, forging layers clearly visible
• Hamon: suguha with a tight nioiguchi, turning back broadly at the bōshi
• Blade length (nagasa): 21.8 cm / 8.58 in (about 7 sun 2 bu)
• Curvature (sori): 0.0 cm (mu-sori)
• Width at base (motohaba): 20.7 mm
• Thickness at base (motokasane): 9 mm (exceptionally thick)
• Weight (blade only): 150 g
• Weight (without scabbard): 210 g
• Condition: very well polished and preserved; a very small edge nick (ha-kobore) about 6 cm from the ha-machi; otherwise essentially flawless and sound
• Mounting: period de-menuki aikuchi koshirae — red-and-green marbled kage-maki-e saya, full ray-skin (sō-same) hilt with a large oyatsubu, ox de-menuki, with a fitted kozuka
• Torokushō (Japanese registration) No.: Nagano 93867