Tachi (inscribed "Hanaji")

A Ko-Aoe Tachi Signed Kanetsugu

A slender sword measuring 79.3 centimeters along the cutting edge bends most sharply near the hilt, the deep waist-curve (koshizori) that marks blades of the late Heian and early Kamakura periods. It was forged by Kanetsugu, a smith who worked in Bitchū Province, the region that today forms the western part of Okayama Prefecture. His name, written 包次 and read Kanetsugu, is cut in large, confident chisel strokes just below the single peg-hole in the tang.

The blade now belongs to the Kurokawa Institute of Ancient Cultures in Nishinomiya, Hyōgo Prefecture. The institute holds it as one of the better pieces in a sword collection that has long been counted among the strongest in private hands.

The Aoe Smiths of Bitchū

Kanetsugu belonged to the Aoe group, a body of smiths who worked along the Takahashi River in Bitchū from the close of the Heian period into the Nanbokuchō era. The earliest phase of their output, running from late Heian to about the middle of the Kamakura period, is called Ko-Aoe, or Old Aoe. Almost all of these men shared the character tsugu (次) in their names: Moritsugu, Sadatsugu, Tsunetsugu, Tametsugu. Records describe Kanetsugu as a pupil of Moritsugu, placing him near the head of the line in the early thirteenth century.

Signed Ko-Aoe blades are not common. The earliest Aoe smiths left only two-character signatures and no dates, and time has thinned their surviving work. That scarcity gives a securely signed example real value to students of the period. On 15 June 1978 this tachi was designated an Important Cultural Property. The Agency for Cultural Affairs notes its handsome shape and the way its forging and temper line show the Ko-Aoe manner with unusual clarity.

What to Look For in the Steel

The surface of an Aoe blade is its signature. Where neighboring Bizen smiths aimed for a tight, even grain, the Aoe workshops produced something visibly different. Collectors call it chirimen-hada, a fine crepe-like figure of wood grain that stands slightly proud of the polished surface. Scattered through it are darker patches known as jifu, set against a faintly bluish ground. The combination has its own name, sumihada. On this sword the grain mixes itame and mokume patterning with those darker spots and a thin dusting of ji-nie, the tiny bright crystals of hardened steel.

Along the edge runs the temper line, here a narrow straight band broken by small irregular waves, with short streaks of activity reaching toward the cutting edge and a soft, slightly sinking border of crystals. The point turns in a small, neat curve. A straight groove is carved down each face and stopped square before the tip.

One detail rewards a close look at the tang. Most tachi carry their maker's signature on the face that turns outward when the sword hangs at the left hip. Kanetsugu cut his on the other side, the one that rests against the body. Several Aoe smiths shared this habit, and it is one of the small regional fingerprints that help identify their work.

Seeing the Blade and the Area Around It

The Kurokawa Institute is a research body rather than a museum that keeps its doors open all year. It welcomes visitors only for two annual exhibitions, each lasting about a month, one in spring from mid-April to mid-May and one in autumn across October and November. Whether the Kanetsugu tachi appears depends on the season's theme, so it is worth checking the current program before making the trip.

The institute sits in the quiet Kurakuen hills above Nishinomiya, an area of leafy residential streets that climb toward Mount Kabutoyama. From Shukugawa Station on the Hankyū Kōbe Line, a bus toward Kashiwadō-chō leaves a fifteen-minute uphill walk to the gate, while a taxi covers the distance in roughly ten minutes. Anyone drawn to swords will find more than one reason to come: the same collection includes two National Treasures, both daggers, alongside a deep run of medieval blades.