Warabite-tō and the Classification of Jōkotō — Sword Forms and Lineages of the Yayoi, Kofun, and Nara Periods

What is jōkotō?

"Jōkotō" is the collective term for swords produced before the establishment of the Japanese sword (curved single-edged sword) — broadly speaking, before the early Heian period (9th century). In terms of form, the mainstream was the straight-sword and double-edged-sword lineage originating from China and the Korean Peninsula, and they are systematically distinguished from the present-day Japanese sword (tachi, uchigatana).

The periodization of jōkotō is roughly as follows:

• Yayoi period (3rd century BCE – 3rd century CE): Continent-imported iron swords arrived
• Kofun period (3rd–7th centuries): Domestic production of straight swords became full-scale
• Asuka and Nara periods (7th–8th centuries): A formal sword system was established under the ritsuryō state
• Early Heian period (9th century): Curved swords (prototype of the tachi) began to appear, ending the jōkotō era

Iron swords of the Yayoi and Kofun periods

When iron goods were brought from the continent during the Yayoi period (3rd century BCE – 3rd century CE), the production and use of iron swords began. Early iron swords were mainly imported goods (of Chinese and Korean origin) because forging techniques were still immature, but during the Kofun period (3rd–7th centuries) domestic sword production became full-scale.

Major sword forms of the Kofun period:

• Kantōtachi: A straight sword with a ring-shaped metal fitting at the tsukagashira (pommel). A form shared with China and the Korean Peninsula from the Three Kingdoms period through the Nanbokuchō period, it was interred in large kofun as a symbol of authority.
• Keitōtachi: A straight sword with a kei-shaped pommel (rectangular with a pointed top). Like the kantōtachi, many have been found as burial items in large kofun.
• Sokantōtachi: A practical straight sword with a plain, undecorated ring pommel.

As a notable excavated example of Kofun-period swords, there is the iron sword excavated from Inariyama Kofun (Gyōda City, Saitama Prefecture, late 5th century). It is a straight sword 73.5 cm in total length, bearing an inscription of 115 characters inlaid in gold on the blade. The inscription contains a reference to "Wakatakeru Daiō," corroborating accounts in the Kojiki and Nihon Shoki, and it was designated a kokuhō (National Treasure) in Shōwa 58 (1983). It is currently held by the Sakitama Historic Site Museum.

Characteristics of warabite-tō

Warabite-tō are swords produced from the Nara through early Heian periods (7th–9th centuries), and the name derives from the shape of the pommel resembling "the bud of a bracken fern (warabi)."

Formal characteristics:

• Pommel: A distinctive inward-curling bracken-bud shape ("tomogane-zukuri" — the tsuka and blade are made from a single piece of iron)
• Blade: Single-edged with a slight curve — which can be considered the prototype of the Japanese sword's curvature
• Nagasa (blade length): Approximately 40 cm (total length around 50 cm)
• Tsuka length: Approximately 12 cm (a length suited for one-handed use)
• Excavation sites: Found in large numbers at sites in Tōhoku and Hokkaidō. Approximately 250 examples have been confirmed nationwide, the majority from Hokkaidō and Tōhoku, followed by sites in northern Kantō

Warabite-tō are closely tied to the culture of the Emishi of Tōhoku, and are considered cavalry weapons excavated from kofun and ancient tombs of the 7th–8th centuries. A particularly distinctive feature that sets them apart from ordinary swords is the tomogane-zukuri construction in which the tsuka is integral with the blade, with no structure for fitting a separate wooden tsuka.

Evolutionary lineage of the warabite-tō

Some researchers have proposed the following line of morphological development for the warabite-tō:

Warabite-tō → kenuki-gata warabite-tō → kenuki-gata ōdachi → Kenuki-gata Tachi → tachi (Japanese sword)

This "warabite-tō origin theory" explains the establishment of the Japanese sword through contact with Emishi culture, but among sword researchers other theories also exist (such as a theory of blade modification from continental straight swords), and the debate over origins continues today.

Swords of the Nara and Asuka periods and the Shōsōin

Swords of the Asuka through Nara periods (7th–8th centuries) became standardized in form alongside the establishment of a weapons system under the ritsuryō state. The swords of this era are collectively called "tachi" (大刀), but they differ from the modern tachi (太刀, curved sword) in being straight-bladed or gently curved.

A famous Nara-period sword, the Shichisei-ken (Seven-Star Sword), is associated with Prince Shōtoku and is currently a jūyō bunkazai (Important Cultural Property) held by Shitennō-ji Temple (Osaka). It is a straight sword with the Big Dipper inlaid in gold, known as one of the most highly decorated surviving examples among jōkotō.

The Shōsōin (Tōdai-ji, Nara) also houses weapons and swords from the Nara period, conveying the sword culture of that era to the present along with 8th-century tōsōgu (sword fittings).

The transition from jōkotō to the Japanese sword

Entering the 9th century (early Heian period), "curved single-edged swords" suited for use in mounted combat — that is, the prototype of the tachi — began to appear. Whether this transition developed from the curvature of the warabite-tō, or whether it arose from exchanges with swords from China and East Asia, remains an important ongoing theme in sword research.

Main differences between jōkotō and the Japanese sword (tachi):

Appreciation of jōkotō and cultural property designation

Because jōkotō are largely excavated artifacts, many have been designated as cultural properties and are held by national and regional museums. For sword enthusiasts, they hold high appreciation value as the "origin of sword culture" — a lineage distinct from the Japanese sword. The Tokyo National Museum and Nara National Museum occasionally put kokuhō (National Treasure)- and jūyō bunkazai (Important Cultural Property)-designated jōkotō on public display.

Jōkotō are treated separately from NBTHK examination subjects (Japanese swords), but they have been established as an independent field of appreciation and research among collectors and scholars, with systematic research into excavation regions and typologies advancing steadily.