Great Sword <Kiriba-Zukuri>

A Straight Sword from the Age Before the Samurai Blade

Of the fifty-five early swords kept in the Shōsōin, the eighth-century repository that stands beside Tōdai-ji temple in Nara, twenty-six were built in one particular way. Their makers set the ridge of the blade high, near the back, and left a wide flat plane that slopes down to the cutting edge. Smiths named this construction kiriha-zukuri. The blade recorded here belongs to that same family, yet it never passed into an imperial storehouse. It came down instead through private hands, and it now rests in a private collection in Fukushima Prefecture, listed since 1989 as an Important Cultural Property.

It is a single sword, classed by the Agency for Cultural Affairs as a work of the Nara period (710–794).

To anyone used to the graceful curve of a later warrior's sword, this weapon looks older and odder, and it is. Swords made in Japan before the curved blade emerged in the mid-Heian period are grouped together as jōkotō, the ancient swords. They are nearly straight, single-edged, and owe much of their shape to Tang Chinese and Korean models that reached Japan along with so much else in the seventh and eighth centuries. The back of this blade is rounded rather than ridged, a finish called maru-mune. The point runs long and tapering, the form sword scholars compare to the snout of a barracuda and call kamasu-kissaki. Sight down the edge and you can just catch a slight inward bend, the faint uchizori typical of the period, ages away from the deep curve of a samurai sword.

Why a Privately Held Blade Earned National Protection

Most swords this old reach us in poor shape. They are pulled from burial mounds, eaten through with rust, their surfaces lost. A blade that was handed down above ground, kept polished, and never committed to the earth is called denseihin, a transmitted piece, and survivors of that kind are few. This one comes through with its steel sound and its polish readable, and it still carries an iron habaki, the collar that grips the base of the blade, which appears to be original to the sword rather than a later replacement.

The examiners who recommended the designation in June 1989 pointed to three things. The forging is close and well controlled. The straight temper line is cleanly and confidently set. And the overall preservation is good, which for a blade of this age counts for a great deal. Taken together these put it among the better transmitted ancient swords known, and that rarity is the heart of its value.

The national record leaves the measured length and weight blank, so no exact figures are published for it. What the record describes instead is the work itself, in the close technical language that sword study has used for centuries.

What to Look For in the Steel

Read the surface first. The forged skin shows a large wood-grain figure, ō-itame, with a burl-like mokume worked through it, straightening into a parallel masame grain near the back and along the flat kiriha bevel. The texture pulls tight across the whole blade. Over it lie a fine scatter of bright crystals, ji-nie, scattered grey patches called ji-fu, and dark threading lines, chikei, that wander through the steel like ink in water.

The temper line, the hamon, runs as a medium straight band, chū-suguha, broken here and there by small waves of ko-midare. Brush-stroke streaks of sunagashi trail along it, and a stray island of hardening, a tobiyaki, sits near the base on the side that faced the body when worn. The crystalline edge is soft and deep. Right at the base the hardening falls away in a marked yakiotoshi, a dropping-off of the temper that is itself a signature of great antiquity.

Follow the blade to the tip. The temper there, the bōshi, makes a shallow wave on one face and runs straight on the other, ending without a turnback in a soft, gently rounded finish.

Then turn the sword and look at the tang. It is ubu, never shortened or recut, closing in a chestnut-shaped kurijiri end, and pierced near the bottom by a single hole. Through that hole a cord once ran, the way these early swords were slung from the waist.

Seeing Ancient Swords Today

This blade is privately owned and is not on regular public view, so a visit to Fukushima will not put it in front of you. The tradition it comes from, though, can be met elsewhere, often in better viewing conditions than a small private holding could offer.

Each autumn the Nara National Museum mounts the Shōsōin Exhibition, which rotates a selection of the imperial repository's treasures into the galleries, ancient swords and their fittings among them. In Osaka, Shitennō-ji holds two kiriha-zukuri blades designated National Treasures, the Shichiseiken and the Heishi Shōrin-ken, both linked by long tradition to Prince Shōtoku and shown on occasion. The Tokyo National Museum keeps jōkotō of its own, several of which can be studied at any time through its online image archive, e-Museum.