Introduction: What is Kantei?

In the world of Japanese sword study, kantei (鑑定) refers to the process of carefully examining a blade to determine its origin, including when, where, and by whom it was made. For signed (zaimei) swords, this can be straightforward, but many blades—especially those from the koto period—are unsigned (mumei), or their signatures (mei) have been lost through shortening (suriage) or deliberately removed (gimei, forged signatures). In these cases, kantei relies entirely on a deep understanding of the sword’s physical features: its shape (sugata), grain pattern (jihada), temper line (hamon), and forging characteristics.

This is where the Gokaden framework becomes invaluable. Developed by Hon’ami Kōson as a classification of the five major swordmaking traditions of the koto era—Yamato-den, Yamashiro-den, Bizen-den, Sōshū-den, and Mino-den—the Gokaden provides a comparative lens through which swords can be evaluated and placed into stylistic contexts. By recognizing which of the five traditions a sword most closely resembles, a student of kantei can narrow down the possibilities and make increasingly precise attributions.

The Gokaden as a Systematic Tool

Each of the five Gokaden traditions has distinctive characteristics based on regional resources, forging techniques, patronage, and aesthetics. These include:

  • Sugata (blade shape and proportions)
  • Hamon (temper line patterns and activity)
  • Jihada (steel grain and forging surface)
  • Boshi (tip temper patterns)
  • Nakago (tang shape and finish)
  • Utsuri, nie, and other internal phenomena

By comparing these traits to well-documented features from each tradition, practitioners can hypothesize a school or individual smith. Even when a blade lacks a mei, its construction often leaves a signature of its own in the steel.

Step-by-Step: Kantei Using Gokaden

1. Identify the Sugata

Start by examining the overall shape and size of the blade. The sugata can reveal the sword’s age and functional context. For example:

  • A deeply curved tachi with ko-kissaki (small tip) suggests late Heian or early Kamakura period—possibly Yamashiro or Ko-Bizen.
  • A wide, powerful blade with ō-kissaki and shallow curvature is likely Nanbokuchō period, possibly Sōshū-den or Chōgi-style Bizen.
  • A short, compact katana with moderate curvature and pointed kissaki may point to Muromachi-period Mino-den, especially if made in Seki.

This immediately helps narrow down time period and regional style.

2. Examine the Hamon

The hamon is one of the most visually informative features. Ask: is it straight (suguha)? Wavy (notare)? Irregular (midare)? Does it contain choji, gunome, hitatsura, or togari? Consider these general guidelines:

  • Bizen-den: Rich choji-midare with ashi and often utsuri.
  • Sōshū-den: Wild midareba or hitatsura with abundant nie, kinsuji, and sunagashi.
  • Yamashiro-den: Subtle suguha with delicate nie and fine utsuri.
  • Mino-den: Bright togari-ba or sanbon-sugi, often grouped in repeating sets.
  • Yamato-den: Straight suguha with masame hada, and sometimes nijūba (double lines) or hotsure.

A well-trained eye can often classify a hamon’s structure and texture as belonging to one of the Gokaden.

3. Inspect the Jihada

The steel grain (hada) is crucial for identifying forging school. Each tradition has tendencies:

  • Yamato-den: Prominent masame-hada (straight grain) or nagare-hada.
  • Yamashiro-den: Ko-itame or nashiji-hada, extremely fine and tightly packed.
  • Bizen-den: Itame and mokume-hada, often with utsuri.
  • Sōshū-den: Mixed mokume and itame with visible chikei and ji-nie.
  • Mino-den: More practical itame-hada, sometimes masame in the shinogi-ji.

Careful study under good lighting reveals the ji’s activity, refining the kantei judgment.

4. Analyze the Boshi and Nakago

The boshi (tip temper) and nakago (tang) offer further evidence. The nakago’s shape, file marks (yasurime), and patina can indicate age and school, while the boshi pattern (round, sweeping, pointed, or with kaeri return) reflects the smith’s habits.

Examples:

  • Sōshū boshi often ends in hakikake (brush-stroke finish).
  • Yamashiro boshi is small, tight, and round with short kaeri.
  • Mino boshi might be tall, with togi-shita (pointed kaeri).
  • Bizen boshi is often rounded with shallow kaeri, matching the hamon.
  • Yamato boshi is typically straight with gentle return, matching suguha.

The yasurime (filing marks) on the nakago can also match tradition: kattesagari for Mino, higaki for Yamato, etc.

5. Cross-Reference with Known Schools and Smiths

After grouping the blade into one of the five traditions, the final step is to match it to a specific school or smith. This relies on references, comparisons, and experience.

For instance:

  • A blade with elegant suguha, ko-itame hada, and a small boshi might be attributed to Awataguchi Yoshimitsu of Yamashiro-den.
  • A flamboyant choji-midare with midare-utsuri and mokume-hada might suggest Fukuoka Ichimonji of Bizen-den.
  • A wide midare hamon with hitatsura and rich ji-nie could point to Hiromitsu or Sadamune in Sōshū-den.
  • A pointed sanbon-sugi hamon with dense itame and clear kattesagari yasurime would likely be Kanemoto of Mino-den.
  • A strict suguha with strong masame and feathery hotsure boshi might signal Tegai Kanenaga or Taima School in Yamato-den.

Often, the result is phrased as a likely attribution, such as:
“Kamakura period, Yamashiro-den, Rai school, possibly Rai Kunitoshi.”

Conclusion

The Gokaden framework is not just a historical classification—it is a living tool for evaluating and understanding Japanese swords. It provides a baseline for comparison, an entry point for attribution, and a bridge between aesthetics and technique. Whether assessing a signed blade or an enigmatic mumei piece, the Gokaden gives practitioners of kantei the vocabulary, structure, and insight to read the blade’s story from its steel.

In the chapters that follow, we will explore case studies of Gokaden-based kantei, working through real examples of unsigned swords and tracing their features back to specific schools, smiths, and eras—proving how this framework continues to reveal the artistry of Japan’s greatest swordsmiths.