NBTHK Papers Explained: Hozon, Tokubetsu Hozon and Japanese Sword Authentication

When purchasing an antique Japanese sword, you may see descriptions such as “NBTHK Hozon papered” or “Tokubetsu Hozon certified.”

For new collectors, these terms can be confusing. What exactly is an NBTHK paper? Does it prove that the sword is genuine? Is Tokubetsu Hozon always better than Hozon? And does an unpapered sword have no value?

This guide explains the NBTHK authentication system and what collectors should understand before purchasing a papered Japanese sword.

What Is the NBTHK?

NBTHK stands for:

Nihon Bijutsu Token Hozon Kyokai
日本美術刀剣保存協会

It is commonly translated as the Society for the Preservation of Japanese Art Swords.

The NBTHK was established in 1948 to help preserve Japanese swords with artistic and historical value. In addition to conducting sword examinations, the organization supports the preservation of traditional sword-making, polishing and mounting techniques. It also operates the Japanese Sword Museum in Tokyo.

The NBTHK examines:

• Japanese sword blades

• Koshirae, or complete sword mountings

• Tosogu, or individual sword fittings

After examination, qualifying objects may receive an authentication or designation paper.

What Is an NBTHK Paper?

An NBTHK paper is a document issued after a sword or sword fitting has passed an official NBTHK examination known as shinsa.

For a sword blade, the paper normally records information such as:

• Type of sword

• Signature or attribution

• Blade length

• Whether the blade is signed or unsigned

• NBTHK certification level

• Date of issue

• Information corresponding to the Japanese sword registration certificate

The paper represents the conclusion of the NBTHK examination panel at the time of examination.

For a signed sword, the panel evaluates whether the signature is considered genuine and consistent with the workmanship of the named swordsmith.

For an unsigned sword, the panel may attribute the blade to a particular smith, school, province or historical period.

The Four Main NBTHK Levels

The current NBTHK system has four principal levels:

1. Hozon

2. Tokubetsu Hozon

3. Juyo Token

4. Tokubetsu Juyo Token

The NBTHK describes these as four progressive levels for swords, mountings and sword fittings. Hozon and Tokubetsu Hozon examinations are generally held several times per year, while Juyo examination is normally held annually and Tokubetsu Juyo examination every two years.

This article focuses primarily on the two levels most frequently encountered by collectors: Hozon and Tokubetsu Hozon.

What Does Hozon Mean?

Hozon Token, written 保存刀剣, can be translated as:

“Sword worthy of preservation.”

Hozon is the standard modern NBTHK authentication level for an antique Japanese sword of recognizable artistic or historical merit.

Under the NBTHK examination standards, a sword made no later than the Edo period may qualify when:

• A signature is judged to be authentic, or

• An unsigned blade can be reasonably attributed to a period, province or school

• The blade retains sufficient artistic quality for appreciation

A sword may still qualify despite some wear, minor flaws or limited repair, provided these issues do not seriously prevent appreciation of the blade.

What Hozon Usually Tells the Collector

A Hozon paper generally indicates that:

• The object is recognized as a genuine Japanese art sword

• A signed blade’s signature has been accepted by the NBTHK

• An unsigned blade has received an attribution

• The blade has sufficient workmanship and condition to be preserved and appreciated

For many collectors, a Hozon paper provides an important level of confidence when purchasing a sword.

However, Hozon does not mean that every sword is of the same quality or value. Two Hozon swords may differ greatly in age, condition, rarity, workmanship and market price.

What Does Tokubetsu Hozon Mean?

Tokubetsu Hozon Token, written 特別保存刀剣, can be translated as:

“Sword especially worthy of preservation.”

Tokubetsu Hozon is the next level above Hozon.

According to the NBTHK standards, Tokubetsu Hozon is intended for swords that have already met the Hozon standard and are considered to have particularly good workmanship and a good state of preservation.

A sword normally needs an existing Hozon paper before it can be submitted for Tokubetsu Hozon alone. The NBTHK also permits Hozon and Tokubetsu Hozon to be applied for at the same examination stage under its current application system.

Tokubetsu Hozon Is More Selective

Factors that may prevent a sword from receiving Tokubetsu Hozon include:

• Significant tiredness from repeated polishing

• Serious flaws

• Repairs that noticeably affect the blade’s beauty

• Re-tempering, known as yaki-naoshi

• An unsigned Muromachi or Edo-period blade that cannot be strongly attributed to an important smith

• A shortened Edo-period blade whose signature has been lost or cut

• Hagire, meaning a crack extending through the hardened cutting edge

The standards are stricter than those for ordinary Hozon certification.

Hozon vs. Tokubetsu Hozon

The basic difference can be summarized as follows:

Paper	General meaning
Hozon	Genuine and worthy of preservation
Tokubetsu Hozon	Higher-quality work in better condition and especially worthy of preservation

Tokubetsu Hozon normally indicates a stronger overall evaluation of the sword’s workmanship and preservation.

However, collectors should not evaluate a sword using the paper level alone.

For example, an important Kamakura-period sword with an old attribution may be historically more desirable than a later sword with Tokubetsu Hozon papers. Conversely, an exceptionally well-preserved Edo-period sword by a respected smith may receive Tokubetsu Hozon and offer excellent craftsmanship at a comparatively accessible price.

The paper is important, but it is only one part of the sword’s complete evaluation.

What Are Juyo and Tokubetsu Juyo?

Above Tokubetsu Hozon are two much higher levels.

Juyo Token

Juyo Token, or 重要刀剣, means:

“Important Sword.”

Only swords that satisfy the eligibility requirements for the Juyo examination may be submitted. Under the current NBTHK procedure, applicants must first have passed Tokubetsu Hozon.

Juyo swords are expected to display extremely high workmanship, importance and preservation.

Tokubetsu Juyo Token

Tokubetsu Juyo Token, or 特別重要刀剣, means:

“Especially Important Sword.”

This is the highest level within the NBTHK system.

It is reserved for outstanding works selected from swords that have already received Juyo status. The NBTHK describes Tokubetsu Juyo works as especially distinguished in workmanship and preservation, with extremely high artistic, historical and academic value.

These higher levels are significantly rarer and are mainly encountered in advanced collections.

Signed and Unsigned Japanese Swords

NBTHK papers are important for both signed and unsigned swords, but they serve slightly different purposes.

Signed Swords: Zaimei

A sword with a signature is called zaimei.

When a signed sword passes Hozon, the NBTHK has accepted the signature as genuine in relation to the blade’s workmanship and other characteristics.

This is important because false signatures, known as gimei, have existed for centuries.

A famous swordsmith’s name may have been added to a blade by another person to increase its perceived value. Therefore, the presence of a signature alone does not prove that the blade was made by the named smith.

Unsigned Swords: Mumei

An unsigned sword is called mumei.

Many genuine and valuable Japanese swords are unsigned. A sword may have originally been unsigned, or its signature may have been removed when the tang was shortened.

When a mumei blade passes NBTHK examination, the paper may give an attribution using the word den, a school name, a province or the name of a particular smith.

An unsigned sword with a strong attribution can still be historically and artistically important.

What Does “Den” Mean on an NBTHK Paper?

The word den, written 伝, is commonly translated as:

• Tradition of

• Attributed to

• In the style or lineage of

However, its meaning is more nuanced than a simple expression of doubt.

In an attribution, “Den” generally indicates that the blade displays the characteristics of the named smith or school, while certain details may extend beyond or vary slightly from the most typical examples.

A Den attribution should not automatically be interpreted negatively.

Its significance depends on the blade, the attribution and the broader historical context.

An NBTHK Paper Is Not the Same as a Registration Certificate

This distinction is extremely important.

An NBTHK paper is a private organization’s appraisal and authentication document.

A Japanese Torokusho, or 銃砲刀剣類登録証, is the government-issued registration certificate required for the lawful possession of a registered sword in Japan.

The registration certificate is issued through the relevant prefectural education authority after the sword has been examined under Japanese law. A registered sword may be legally possessed in Japan regardless of whether it has an NBTHK paper.

Therefore:

• The NBTHK paper concerns attribution, authenticity and artistic evaluation

• The registration certificate concerns the sword’s legal registration in Japan

A sword may have a registration certificate but no NBTHK paper.

It may also have both documents.

Does an NBTHK Paper Prove the Sword’s Market Value?

No.

An NBTHK paper does not establish a fixed financial value.

The market price of a Japanese sword depends on many factors, including:

• Swordsmith or school

• Historical period

• Quality of the jigane

• Quality and style of the hamon

• Condition

• Amount of polishing

• Presence of flaws

• Originality of the nakago

• Signature

• Length and shape

• Rarity

• Provenance

• Quality of the koshirae

• Current collector demand

Tokubetsu Hozon will often support a higher market value than Hozon when comparing similar swords. However, the paper level should never be used as the only basis for determining price.

Does a Paper Guarantee That the Sword Has No Flaws?

No.

A papered sword may still have:

• Kitae-kizu, or forging flaws

• Ware, or openings in the steel

• Fukure, or blister-like forging defects

• Small areas of rust

• Scratches

• Old polishing wear

• A shortened tang

• Later repairs

Certain defects may be acceptable at the Hozon level when they do not prevent appreciation of the sword.

Collectors should always examine detailed photographs and read the condition description carefully.

A certification paper is not a replacement for a condition report.

Can an Old NBTHK Paper Still Be Trusted?

Collectors may encounter older papers such as:

• Kicho

• Tokubetsu Kicho

• Koshu Tokubetsu Kicho

These belong to earlier NBTHK certification systems.

Old papers can still be useful historical documents, but they are not automatically equivalent to the current Hozon and Tokubetsu Hozon system. For an expensive purchase, collectors may prefer a sword that has passed examination under the modern system.

The NBTHK offers services relating to papers it has issued, including ledger inquiries and certain certificate procedures. However, the NBTHK also warns that a matching ledger entry alone cannot guarantee that a physical certificate has not been forged or altered.

How to Check Whether the Paper Matches the Sword

Before purchasing, compare the certificate with the sword carefully.

Check the following details:

1. Sword Type

Confirm whether the paper identifies the object as a katana, wakizashi, tanto, tachi, naginata or another type.

2. Signature

The inscription on the nakago should correspond to the inscription recorded on the paper.

3. Blade Length

The cutting-edge length, or nagasa, should match the certificate.

Small measurement differences may result from measurement methods, but a major discrepancy requires investigation.

4. Number and Position of Mekugi-ana

The number and placement of peg holes in the nakago should be consistent with the paper’s oshigata or recorded information.

5. Registration Information

For papers that contain Japanese registration information, confirm that it corresponds with the Torokusho accompanying the sword.

6. Certificate Condition

Look for suspicious alterations, replaced photographs, disturbed seals or inconsistent paper construction.

When purchasing a high-value sword, obtaining an expert opinion is advisable.

Does a Sword Without NBTHK Papers Have No Value?

No.

A sword may lack NBTHK papers for many reasons:

• It has never been submitted

• The owner did not want to pay the examination fees

• The owner did not want to wait for the examination

• The sword was recently discovered

• The sword is located outside Japan

• The owner believes its identity is already clear

• Its previous paper has been lost

An unpapered sword is not automatically fake or worthless.

However, an unsigned or highly valuable sword without papers normally requires more careful examination. The buyer must rely more heavily on the blade itself, the seller’s expertise, provenance and independent specialist opinions.

Does Hozon Mean the Signature Is Genuine?

In general, when a signed sword receives a modern Hozon paper naming that swordsmith, the NBTHK has accepted the signature as genuine.

However, buyers should still confirm that:

• The paper belongs to that exact sword

• The paper has not been altered

• The blade has not been substituted

• The certificate details match the nakago and blade

The paper and the sword must always be considered together.

Is Tokubetsu Hozon Always Worth Paying More For?

Not necessarily.

Tokubetsu Hozon can be desirable because it indicates a higher evaluation of workmanship and preservation. It may also make a sword easier to sell in the international collector market.

Nevertheless, the best choice depends on the collector’s priorities.

A collector focused on history may prefer an older Hozon blade with an interesting attribution. A collector focused on pristine workmanship may prefer a Tokubetsu Hozon Shinshinto or Edo-period sword.

The sword itself should always come first.

Why NBTHK Papers Matter to International Collectors

For collectors outside Japan, NBTHK papers provide a recognized reference point.

Most overseas buyers cannot examine hundreds of authenticated Japanese swords in person. A modern NBTHK paper can help reduce uncertainty concerning:

• Signature authenticity

• School or smith attribution

• Historical period

• Basic artistic merit

• General eligibility for preservation

This is especially useful when buying remotely.

However, papers cannot fully communicate the beauty of the steel, the brightness of the hamon or the three-dimensional activity visible when a sword is viewed in hand.

Final Thoughts

NBTHK papers are among the most widely respected authentication documents in the Japanese sword market.

A Hozon paper generally confirms that a sword is genuine, identifiable and worthy of preservation.

A Tokubetsu Hozon paper represents a higher assessment, recognizing stronger workmanship and preservation.

However, collectors should remember that:

• The paper must match the sword

• Certification does not establish a fixed market value

• A papered sword may still have flaws

• A registration certificate and an NBTHK paper serve different purposes

• An unpapered sword is not automatically worthless

• The blade itself remains the most important object of study

The ideal purchase combines reliable certification, an accurate condition description, fair pricing and a sword that genuinely appeals to the collector.

At Katte-ya, we carefully describe the signatures, certificates, condition and visible characteristics of each Japanese sword. When an NBTHK paper is included, photographs and relevant certification details are shown in the product listing whenever possible.

Explore our collection of authentic Japanese swords and discover a piece of Japanese history to preserve for the future.

This article is intended as a general guide for collectors. NBTHK examination results reflect the organization’s judgment at the time of examination and should be considered together with the physical condition, provenance and individual characteristics of each sword.


Explore our Japanese Sword Collection → https://katte-ya.jp/collections/japanese-sword