The Technique and Appraisal of Suriage: Modification from Tachi to Uchigatana, Value Assessment, and How to Identify It

What Is Suriage — Blade Modification Born of Changing Times

Suriage is one of the modification procedures that alter the form of a nihontō; specifically, it refers to the process of shortening the overall length of the blade (including the nagasa) by cutting down the nakago from its butt end. Shortening by suriage also reduces the nagasa, and with the nakago section reduced, the grip of the tsuka (hilt) and the overall balance of the sword change; the modification is often carried out for the purpose of improving practical usability.

Regarding the etymology of the word "suriage," the prevailing theory is that it derives from the process of trimming and polishing the cut surface of the nakago (suri-ageru, "to grind up").

The historical background behind the large-scale carrying out of suriage is that large tachi made during the Kamakura through Nanbokuchō periods became inconvenient to use as battle tactics changed (from cavalry to infantry combat). Long tachi were not suited to being worn at the waist in the manner of the uchigatana, and it became common practice to cut down the nakago and shorten them for reuse as uchigatana. From the latter half of the Muromachi period through the early Edo period, many of the finest kotō pieces were subjected to suriage and used as uchigatana.

Types of Suriage — Classification by Degree of Shortening

Suriage is classified as follows according to the extent of shortening.

Ko-suriage

The amount cut from the nakago is relatively small, and part of the original nakago remains. In most cases the original mei (the tōkō's signature) survives, and some of the original mekugi holes also remain. Part of the yasurime (file marks) on the nakago can be seen continuing.

Ō-suriage

A state in which the nakago has been drastically cut down. The original mei is often partially or completely lost. The original mekugi hole has been removed and a new one drilled. The overall shape of the nakago has changed.

Kanzen suriage

The original nakago has been completely removed and the original mei is completely lost. The entire nakago is newly formed at the time of suriage or later. No original yasurime remain, and new yasurime have often been applied.

Treatment of the Mei — Orekaeshi-mei and Kiwame

How the original mei is handled at the time of suriage is an extremely important question in appraisal.

Orekaeshi-mei

When part of the original mei remains in a particular section of the nakago, the procedure of folding back the end section of the shortened nakago (on the machi side) to preserve the portion bearing the mei is called orekaeshi-mei. By this means, the original mei is preserved hidden inside the shortened nakago. The presence of an orekaeshi-mei is an important positive factor in the value assessment of a suriage sword.

Whether an orekaeshi-mei exists can be confirmed by removing the tsuka (hilt) and carefully examining the area around the mekugi holes and the sides and end of the nakago.

Soe-mei and Daimyo-mei

After suriage, the daimyo or sword dealer who commissioned the work sometimes added their own name as a mei to the nakago. This is called a soe-mei or daimyo suriage. In the case of famous swords said to have been subjected to suriage by prominent warriors such as Toyotomi Hideyoshi, Tokugawa Ieyasu, and Date Masamune, such soe-mei may survive.

Kiwame and Nochi-mei

The act of a later sword appraiser (such as the Hon'ami family) inscribing a mei as an appraisal result on a suriage sword whose original mei has been lost is called kiwame, or "entering a nochi-mei." Suriage swords bearing kiwame inscriptions by noted appraisers such as Hon'ami Kōon and Hon'ami Kōchū carry historical value in their own right.

Features of the Nakago after Suriage — Identification in Appraisal

A sword that has been subjected to suriage can be confirmed as such by examination of the nakago. The characteristic features visible on a suriage nakago are as follows.

• Shape of the nakago tip (cut surface): The cut nakago tip produced by suriage often has a different shape from the original nakago tip. The nakago tip of the original tachi is often a long, tapering kengata nakago or hoso-nakago, but these distinctive shapes are lost after suriage.
• Presence of multiple mekugi holes: A suriage sword may have both the original mekugi hole and a new one drilled after suriage. When an old mekugi hole remains near the tip of the nakago and a new mekugi hole is in a position close to the tsuka joint, this is evidence that suriage has been carried out.
• Discontinuity of yasurime: When the pattern of yasurime applied to the original nakago changes partway through or is unnaturally interrupted, this indicates that the original nakago was cut by suriage and new yasurime were applied to the remaining section.
• Changes in nakago width and cross-section: The original tachi nakago tends to be relatively slender and flat, but when reshaping has been carried out to form a nakago suitable for an uchigatana after suriage, the cross-sectional shape may change.

The procedure for reading the full provenance of a sword from the nakago's yasurime, mekugi holes, and mei is also explained systematically in the Complete Guide to Reading the Nakago.

Effects of Suriage on Value

Suriage has complex effects on the value assessment of a nihontō.

Negative factors:

• Loss of the original mei
• Loss of the original nakago shape
• Alteration from the original manufacturing condition
• Increased polishing history

In particular, when the original mei is lost through kanzen suriage, the power to authenticate the sword as the original blade is weakened, even when a kiwame mei is present.

Positive factors or neutral aspects:

• Swords subjected to suriage by historically prominent figures (Toyotomi suriage, Tokugawa suriage, etc.) gain added value from that historical background.
• When an orekaeshi-mei has been preserved, this contributes to preservation of value.
• When the condition of the blade (nagasa) and its quality (deki) are sound, they are assessed separately from the condition of the nakago.

Distinguishing from Later Fraudulent Suriage

Points of focus for appraisal when distinguishing legitimate suriage of the Muromachi through early Edo periods from later fraudulent modification (false suriage):

• Consistency of aged rust patina (sabi-iro): With legitimate suriage, rust that has accumulated over the years since the suriage was carried out is distributed uniformly across the entire nakago. With fraudulent suriage (modern alteration), the color and quality of the rust differ unnaturally from other parts of the blade and nakago.
• Techniques and tool marks of the yasurime: The tool marks and working precision of pre-Edo yasurime differ from those of the modern era and later. Yasurime that are unnaturally crisp require caution.
• Typological consistency of nakago shape: A check of whether the nakago shape after suriage is consistent with the nakago shapes of the period and school in which the sword was made. Where there is inconsistency, later modification is suspected.

Suriage is a culture of modification that emerged necessarily in the history of nihontō, and is in itself proof of the demands of the age and of tōshō craftsmanship. For the appraiser, examining a suriage sword is also an act of reading multiple historical cross-sections at once — from the period of manufacture through the period of modification to the present day.