Tachi Sword (inscribed Kagemitsu Osafune, Bizen Province /

A Tachi Signed by Osafune Kagemitsu

The signature on this curved sword reads Bizen no Kuni Osafune ju Kagemitsu, "Kagemitsu, resident of Osafune in Bizen Province." It identifies one of the most accomplished swordsmiths of the early fourteenth century. The blade measures 77.6 centimetres along the edge and weighs 854 grams, with a broad body and a fairly deep curve that gives it a noticeable heft in the hand. It is held by the Kurokawa Institute of Ancient Cultures in Nishinomiya, Hyogo Prefecture, and is registered as an Important Cultural Property.

A second inscription was once cut into the reverse of the tang, recording the year and month of manufacture. Wear has rendered it unreadable, and the official designation name preserves the gap by writing the date as blank characters. Kagemitsu's dated works run from 1306 to 1334, so even without the lost year the sword can be placed firmly in the closing decades of the Kamakura period.

Kagemitsu and the Osafune School

Bizen Province, in the southeast of present-day Okayama Prefecture, was the most prolific sword-producing region in medieval Japan. Along the Yoshii River clustered several schools, and the one that came to dominate took its name from the village of Osafune. Mitsutada founded the line in the mid-Kamakura period; his son Nagamitsu carried it forward; and Kagemitsu, Nagamitsu's son, is counted as the third head of the school.

Kagemitsu worked in a quieter register than his father. Nagamitsu favoured flamboyant clove-shaped temper patterns, while Kagemitsu pulled the design inward toward control and clarity. What sets him apart is a temper pattern he is credited with inventing, the kataochi-gunome, a row of half-collapsed crests that one connoisseur likened to wave tops leaning under a steady wind. His son Kanemitsu inherited both the workshop and this signature motif before later moving toward grander forms in the Nanboku-chō era.

Why the Blade Was Designated

Two qualities carry the sword. The first is the steel itself. Kagemitsu's forging is often judged finer than his father's, and here the surface shows a tight ko-itame grain, a wood-like pattern of small swirls, scattered with fine crystalline particles. Across it drifts a pale, cloudy reflection called midare-utsuri, a misty band that hovers above the temper line and is one of the hallmarks of Bizen work at its peak.

The second is the temper line, the hamon, which is unusually lively for this smith. Small clove and small zigzag elements mix with his trademark half-collapsed crests. Among them appear rounded shapes the Japanese call kawazuko, "tadpole" cloves, and isolated patches of hardening that float clear of the main line. Short bright streaks reach toward the edge, the misty nioi runs deep, and faint sweeping lines like a broom drawn through sand cross the surface. The blade survives in good condition, and the combination of refined steel and a varied, legible temper places it among Kagemitsu's stronger pieces.

What to Look For

The detail most worth seeking out is a carving near the base of the blade on the side that faced outward when the sword was worn. It depicts a ken, a straight double-edged ritual blade, and its grip is shaped as a sankoshō, a three-pronged vajra used in Esoteric Buddhist ritual. The vajra-hilted sword is an emblem of Fudō Myōō, the wrathful guardian whose blade cuts through delusion, and its presence on the steel is a request for that protection.

There is a twist in how it reads today. At some point the sword was shortened, a common fate for old blades reworked to suit changing fashions or owners. The shortening pulled the carving down into the mounting, so the vajra grip now sits hidden beneath the metal collar and the hilt. Only the straight blade of the engraved ken remains in view, a fragment of a longer image that the steel once carried in full.

One more clue rewards a close look. The collar at the base, the habaki, is decorated with a triple-hollyhock crest. That emblem belonged to the Tokugawa house, which tells us the sword passed through the family's hands at some stage in its long life, though the route by which it reached them is not recorded.

Seeing It in Person

The Kurokawa Institute sits on a wooded hillside in the Kurakuen district of Nishinomiya, between Osaka and Kobe. It is a research institution rather than a permanent museum, so its collection of Japanese and Chinese art is shown only during two exhibition seasons each year, roughly a month in spring and a month in autumn. Whether this particular sword is on display depends on the theme of the current show, so checking the institute's exhibition schedule before a visit is wise.

The hilltop setting is part of the appeal. The surrounding Kurakuen and Shukugawa areas are known for their walking routes, and in early April the Shukugawa riverbank draws crowds for one of the Kansai region's better-loved cherry-blossom displays. The port city of Kobe and the shopping streets of Osaka are both within easy reach by train, making the institute a quiet detour on a wider trip rather than a destination on its own.