Small Blades, Sword Hilt Ornaments, and Hair Pins—The Three Auxiliary Components of Japanese Sword Fittings and Blade Mounting Culture

The Three Auxiliary Components of Sword Decoration

Japanese sword sheaths (saya) often incorporate three types of "auxiliary components" in addition to the blade itself. These are far more than mere accessories—they are crafted works that serve as the artistic foundation for unified sword decoration, and they hold significant market value as independent subjects of appreciation and collection.

Small Blades (Kogata) and Sword Hilt Ornaments (Kozuka)

A small blade (kogata) is a small blade-shaped implement (tousu) housed in a groove on the side of the sheath called a "kozuka-bitsu" (small blade compartment). It served practical everyday purposes (cutting cord, processing food, etc.) and doubled as a self-defense tool, with blade lengths typically around 10 cm.

A kozuka refers to the hilt of the small blade, and the portion visible from the sheath becomes the artistic centerpiece of the design. The material consists of metals such as red copper (shakudo), silver, gold, or iron, with decorative techniques including high relief carving, shallow carving, and inlay (zougan), concentrating the craftsman's individuality and skill.

Renowned kozuka makers include the Goto clan (Goto family type), Yokoya Soumin, and artisans from the Nara ittou-bori tradition. Kozuka are sometimes subject to NBTHK (Nippon Bijutsu Token Hozonkai) examination, and exceptional pieces are designated as particularly important auxiliary components.

Hair Pins (Kogai)

A kogai is an elongated metal rod-shaped implement housed on the opposite side of the sheath, originally carried by samurai as a hair-grooming tool (for adjusting topknots and scratching the scalp).

Characteristics:

• Approximately 20 cm in length, with a flat or pointed tip
• Made of the same metal craft materials as kozuka (red copper, silver, gold, etc.)
• Design typically matches the corresponding kozuka and sword guard (tsuba) to create visual unity
• From the Edo period onward, the decorative aspect became more prominent than practical use

Additionally, there is a tradition that kogai were also used on battlefields by inserting them into the ear of a severed head and tying a wooden tag bearing a military commander's name to identify the deceased. This suggests they served both practical and ceremonial functions.

Market Value of the Three Components

Furthermore, a set of five pieces consisting of the three-piece set plus spare small blades and kogai is called a gosho-mono (five-piece set). Ranking above the three-piece set in formality, surviving examples of five-piece sets matched in both craftsman and design are extremely rare.

A three-piece set consisting of kozuka, kogai, and menuki (decorative metal fittings embedded in the hilt) is called a misho-mono (three-piece set). When all three pieces match in both craftsman and design, their rarity and market value increase significantly. Signed masterpieces from the early through late Goto family are held in numerous Western museum collections and command international market competitiveness.

The Goto Family—Official Three-Piece Set Makers to the Shoguns

Essential to any discussion of the history of three-piece sets is the Goto family. The founder, Goto Yuujou (1440–1512), was a native of Mino Province who served the 8th shogun, Ashikaga Yoshimasa, and received official recognition to practice metalwork as a profession, establishing the family's status as the shogun's official metal craft dynasty. Subsequently, the Goto family served seventeen generations of successive powers—from the Ashikaga through the Oda, Toyotomi, and Tokugawa families—reigning at the pinnacle of three-piece set craftsmanship for approximately 400 years.

The characteristic technique of Goto family three-piece sets was the standardized style of high relief carving on shakudo fish-roe ground (shakudo nanako-ji). Fine granular fish-roe patterns were densely applied to a shakudo ground (red copper—an alloy of copper and gold with a darkened finish), and animals, plants, and historical figures were rendered in high relief above. This technique, called "ie-bori" (family carving), functioned as the most prestigious style of auxiliary component required for presentation pieces to the shogun and daimyo families.

Yokoya Soumin and the Rise of "Merchant Carving"

While the Goto family continued to uphold their "ie-bori" formality, Yokoya Soumin (1670–1733) initiated a new movement during the Genroku era. Trained in the Goto style, Soumin established his independence around 1690 (Genroku 3) and pioneered a liberated "machi-bori" (merchant carving) free from constraints of subject matter, material, and composition. Wielding diverse techniques including openwork carving, cloth-pattern inlay, and side-cut carving, he brought the beauty of sword mounting accessories not only to the warrior class but to prosperous merchant families as well. Soumin's emergence marked a pivotal moment that introduced competition and diversity to the Goto-family-centered world of auxiliary components.

Alongside Yokoya Soumin, the metal craftsmen known as the "Nara Three Masters" (Nara Sansaku) are celebrated as leading figures of the Edo mid-period "machi-bori" movement. The three exemplars were Sugiura Norioki, Nara Toshihisa, and Tsuchiya Yasuchika, who established their distinctive styles through realistic animal and plant representation and refined hair-line carving. They departed from the Goto family's standardized style and expanded the expressive range of auxiliary components through free composition and diverse techniques, rivaling Yokoya Soumin in significance.

Dual-Compartment Mountings and Storage Design

A sword mounting that houses both a small blade and a kogai in the sheath is called a morobistu-koshirae (dual-compartment mounting). Grooves are provided on the front (blade side) for the small blade and on the back for the kogai, such that when the sheath is held, the metal craft decoration of the hilts is visible from the outside. Three-piece sets (or two-piece sets) in which the designs of the small blade and kogai match those of the sword guard and menuki represent the highest aesthetic achievement, embodying a unified visual world.

Evaluation in the Modern Market

Three-piece sets are traded individually in the international art market, and exemplary Goto family pieces are held in major Western museums (the Metropolitan Museum of Art, the Victoria and Albert Museum, etc.). On TOUKENZA, in addition to individual small blades, kogai, and menuki, matched three-piece sets are also featured, with provenance, preservation condition, and the presence or absence of NBTHK (Nippon Bijutsu Token Hozonkai) authentication significantly influencing market price.

Key Points for Appreciating Sword Mounting Accessories

When examining small blades and kogai, attention should be paid to several essential elements.

Confirming the Material: Verify which metal serves as the base—red copper (shakudo), silver, gold, or iron. Goto family works typically use a shakudo fish-roe ground as the standard. Many pieces also employ shibuichi (an alloy of copper and silver) or pure copper (suaka, high-purity copper).

Identifying the Carving Technique: Various techniques are employed, including high relief carving (three-dimensional carving rising from the ground), shallow relief carving, hair-line carving (line engraving), and inlay (embedding gold, silver, or red copper). Goto family high relief carving is noted for its resistance to corrosion and increasing depth with age.

Examining the Signature: The Goto family maintained the convention of signing their works from founder Yuujou onward. Signatures such as "Yuujou" or "Munejou" engraved on the back or at the base of the hilt are crucial to authenticating authenticity. Many Yokoya Soumin works bear the "Soumin" signature, but later copies are common, making confirmation of authentication results essential.