Tachi (inscribed Nagamitsu)

A Tachi Signed Nagamitsu: A Late-Kamakura Bizen Blade in Original Form

Near the upper edge of the tang, on the side that faced outward when the sword hung from a warrior's belt, two characters are cut into the steel: Nagamitsu. The signature belongs to one of the most accomplished swordsmiths of medieval Japan, working in the Bizen province workshops of Osafune around the close of the thirteenth century. The blade measures 77.5 centimeters with a curvature of 3.0 centimeters, and it survives in its original length, never shortened to fit a later fashion. It is held today by a private owner in Tokyo and is registered as an Important Cultural Property.

Tachi were long swords worn edge-down, suspended from cords, the weapon of mounted warriors before the shorter uchigatana came into favor. The deep curve concentrated toward the hilt, called koshizori, marks this piece as a product of the Kamakura age, when a tachi was meant to be drawn and swung from horseback.

Nagamitsu and the Osafune Tradition

Bizen, in the south of what is now Okayama Prefecture, was Japan's most productive sword country. Along the Yoshii River, the town of Osafune grew into a forge community so dense that later writers spoke of a thousand smithies. The Osafune school was founded by Mitsutada, and Nagamitsu, recorded as his son, carried the line to its height. He trained a generation of smiths who followed him, among them Kagemitsu and Sanenaga, and he left more signed surviving blades than almost any other early master. Six of his works carry the rank of National Treasure.

His early blades echo his father's taste for bold, flame-like temper patterns; his later work moves toward quieter straight lines. The sword described here belongs to the flamboyant side of his range. The Agency for Cultural Affairs calls it an outstanding example of the Osafune Nagamitsu hand, and it was entered onto the national register of Important Cultural Properties on August 29, 1950.

The blade arrives with a sword mounting that is itself part of the designation. This uchigatana koshirae, judged to date from the Momoyama period some three centuries after the blade was forged, has a scabbard finished in gold nashiji lacquer, a hilt bound in purple cord over white rayskin, and metal fittings carved in high relief with peonies and Chinese guardian lions. A fine blade and a richly dressed mounting, paired across the centuries, were preserved together as a single object of value.

How to Read the Blade

What separates a celebrated Bizen tachi from an ordinary one lives in details that reward slow looking. The temper line here, the hamon, runs in clove-shaped choji mixed with rounded gunome and occasional pointed peaks, with fine lines called ashi reaching toward the edge. This is the lively, irregular pattern that made Nagamitsu's name. Toward the tip, the temper continues in the same restless rhythm before turning back in a shallow sweep.

Look into the body of the blade and a faint, cloudy reflection rises along its length. This is utsuri, a shadow-like figure in the steel that appears in good Bizen work and is difficult to reproduce. The grain of the forging is itame, a pattern resembling the rings and burls of cut timber. The crystalline structure of the temper is described as deep in nioi, meaning the boundary glows like mist rather than breaking into individual sparkling grains.

The tang carries its own evidence. Because the blade was never shortened, the original file marks survive, slanting gently downward, and the end is shaped to a rounded chestnut form. An unaltered tang keeps the maker's signature in its first position and lets a viewer trust the line directly from smith to sword, which is part of why an original-length signed Nagamitsu is prized.

Where to See Nagamitsu's Work Today

This particular blade is privately owned and is not on public display, so a traveler cannot expect to view it. Several of Nagamitsu's finest swords, however, are accessible through public museums, and seeing any of them gives a direct sense of the hand behind the Tokyo blade.

The most famous is the Daihannya Nagamitsu, a National Treasure held by the Tokyo National Museum in Ueno Park. It is shown only at intervals, roughly once every one to three years, so checking the museum's current exhibition listings before a visit is essential. To stand at the source of the tradition, travel to the Bizen Osafune Sword Museum in Setouchi City, Okayama. The museum rotates its display of Bizen blades several times a year and houses an active forge where smiths, polishers, scabbard makers, and hilt binders work in view of visitors. Monthly demonstrations of traditional forging, in which steel is heated past 1,200 degrees and hammered, draw sword enthusiasts from around the world.

Other Nagamitsu blades designated National Treasures are kept at the Hayashibara Museum of Art in Okayama, the Tokugawa Art Museum in Nagoya, and the Sano Art Museum in Mishima, Shizuoka. Each rotates its holdings, so a sword may or may not be on view on any given day.