The World of Tōsu (刀子)—Craft Culture of Small Blades Continuing from the Nara and Heian Periods

What Is Tōshi — A Form of the "Ancestor" of the Japanese Sword

"Tōshi (刀子)" is a collective term for small blades with lengths typically between approximately 10 and 30 centimeters. The term derives from the Chinese "刀子 (dāozi)" and represents a concept and physical object that came from the continent before the Nara period and took root in Japan. It is believed that knowledge was transmitted through Chinese classical texts first, and then as actual objects were imported, manufacturing techniques were also transmitted.

Under the ritsuryo system of the Nara period (710–784), tōshi were officially recognized as portable items that could be worn by nobility and officials. In contrast to the tachi, which were large military blades, tōshi were positioned as multipurpose practical tools with the following functions:

• Writing (scraping/shaving books)
• Dining (cutting food ingredients)
• Medicine (surgical procedures)

The breadth of their functions was one reason why tōshi became established in court culture over a long period.

A term often confused with tōshi is "kogata-na (小刀)". In modern Japanese, "kogata-na" refers generally to any blade with a short cutting edge, but some scholars trace its origins back to the practicality of tōshi — their portability and versatility. Even though terminology changed over time, it is believed that the functionality itself — "a small, portable blade" — was continuously passed down.

Use of Tōshi at the Heian Court — Everyday Tools of Literary Nobility

With the arrival of the Heian period (794–1185), tōshi became deeply integrated into court culture. Scenes depicting tōshi as everyday tools of the nobility can be seen in Heian literary works such as The Pillow Book and The Tale of Genji. In an age when writing and books were the foundation of power, tōshi functioned as a cultural accessory beyond merely being a blade.

A particularly important use was "削り (shaving)" — processing thin strips of bamboo or wood to create "削り花 (shaved flowers)" and others — and cutting ryōshi (decorated paper for writing). In the Heian court where manuscript culture flourished, tōshi were nearby tools, maintained on desks like "a type of writing implement". The sight of tōshi placed alongside brush, inkstone, and writing paper symbolized the daily life of intellectuals of the time.

In court ceremonies, tōshi-wearing was recorded under names such as "御帯刀 (mi-hakashi)" and "御刀 (mi-tono)", and the materials of handles and scabbards were strictly determined according to rank. The fact that differences in materials themselves served to visualize official rank demonstrates that tōshi held symbolic meaning beyond their practical use.

The practical uses carried out by tōshi were diverse:

• In writing scenes, they were used as tools to scrape away thin layers of paper where characters had been mistakenly written in ink.
• In dining scenes, they were used as small blades to cut and divide fruits and dried fish.
• Use in medical contexts is also documented.

The multipurpose character of tōshi as utilitarian blades is considered one reason they became so widely established within the court.

The Craft Development of Tōshi — Inheritance from the Shōsōin

The Shōsōin of the Nara period houses multiple tōshi decorated with gold and silver inlay. Examples such as the "urushi-saya tōshi (漆鞘刀子)" and "kingin-hyōmon-saya tōshi (金銀平文鞘刀子)" clearly demonstrate that tōshi of that period functioned not merely as practical items but as "crafted works" and "prestige goods".

The techniques used in these Shōsōin tōshi — lacquer painting, gold and silver inlay (zougan), and carved arabesque patterns — were inherited by the sword fittings (koshirae) of the Heian and Kamakura periods, becoming one source of Japanese metalcraft and lacquerwork. The process in which continental designs merged with Japanese sensibility is clearly marked in the Shōsōin tōshi.

The "kingin-hyōmon-saya tōshi" takes its name from hyōmon (平文), a technique in which thin sheets of gold or silver are cut into pattern shapes and pasted onto a lacquered surface, then polished and finished. The fact that such labor-intensive and sophisticated decorative techniques were lavishly applied even to small portable tōshi speaks to the high value placed on craftsmanship at that time.

The Relationship Between Tōshi and Japanese Swords — The Transition from Straight to Curved Blades

Tōshi is also an important presence in considering the evolution of Japanese sword forms. Both tōshi and tachi of the Nara period were "chokutō (直刀)" — blades with no curve, remaining straight — but from the mid-Heian period (around the 10th century), "sori (反り)," or curvature, began to appear in blades, and the "wantō (湾刀)," which resembled the shape of modern Japanese swords, was born.

Behind this change in form were factors such as ease of handling in mounted combat and changes in Japan's terrain and combat methods. When considering swift blade draws and cuts from horseback, it is self-evident that a curved blade is more practical. The fact that similar curvature began to appear in small blades like tōshi speaks to how the wave of formal evolution extended across all bladed weapons, regardless of size.

Regarding the factors behind the emergence of curve in blades, multiple elements have been pointed out, including the development of forging techniques and changes in purpose of use, and it is said the phenomenon cannot be reduced to a single cause. In any case, the fact that the design of curve extended even to small tools like tōshi attests that sword makers of the time took strong interest in the very form of the blade itself.

Position of Tōshi in the Modern Era

In modern times, tōshi is receiving renewed attention among sword enthusiasts as "the precursor to the Japanese sword". In sword museums and national museums, tōshi from the Shōsōin and archaeological digs are sometimes displayed in special exhibitions and have become an indispensable presence in exploring the roots of Japanese sword culture. As physical materials linking the ancient and modern eras, they also hold high academic value.

Additionally, some modern sword smiths undertake tōshi production as an effort to study and restore techniques from the Nara and Heian periods, and valuable practical work continues from the perspective of ancient blade research. By recreating past techniques with modern hands, knowledge about manufacturing that cannot be clarified by written documents alone is being accumulated.

How Tōshi Is Treated in the Contemporary Sword Market

Most tōshi were manufactured as unsigned (mumeiji) — lacking the sword smith's signature — practical items, a characteristic that differs from the framework of appreciation and authentication of Japanese swords, which emphasize signatures and form. The majority of extant old tōshi are preserved as museum holdings and have limited opportunity to circulate in the antique market available to private collectors. For readers wishing to deepen their appreciation of bladed weapons, viewing actual examples and their quality and design in museum displays would be the most reliable entry point to understanding tōshi as a craft culture.