What is the Kazuuchi-tou: Mass Sword Production in the Muromachi Period and the Reality Born from Warfare

The term "kazuuchi" (数打ち) refers to practical swords mass-produced through simplified forging processes from the late Muromachi period through the Sengoku period to meet the enormous demand created by warfare. Standing in contrast to "chumon-uchi" (注文打ち)—swords meticulously crafted one by one—kazuuchi were produced in large quantities at production centers such as Bizen Osafune and Mino Seki. This article examines the background and reality of kazuuchi-tou and its impact on sword history through historical sources.

The Ōnin War and the Explosion in Sword Demand—From Muromachi to Sengoku

The Ōnin War (1467–1477), which erupted in 1467 (Ōnin 1), was a great conflict that reduced Kyoto to ashes for eleven years. Simultaneously, it became a turning point that fundamentally transformed the history of the Japanese sword. Until then, demand for swords had centered on producing fine blades for formal warrior belts and temple and shrine offerings, with sword makers adhering to meticulous craftsmanship with small numbers of skilled artisans. However, following the Ōnin War, warfare spanning over a century into the Sengoku period demanded practical swords on an unprecedented scale.

As large numbers of foot soldiers (ashigaru) and rural samurai (jizamurai)—soldiers of lower-class origin who previously could not afford swords—appeared on the battlefield, demand for affordable, practical tachi (打刀) skyrocketed. Powerful daimyo, needing to equip tens of thousands of troops under their command, placed massive orders with sword-producing regions, forcing craftspeople to prioritize quantity over quality in their production systems.

The Reality of Kazuuchi-tou—The Merits and Demerits of Mass Production

"Kazuuchi" stands in sharp contrast to master craftsmen who spared no time and skill in creating a single sword. Instead, it denotes swords produced in large quantities with an emphasis on efficiency. The characteristics of kazuuchi produced in large quantities following the Ōnin War are as follows:

Simplified Forging Processes: The number of folding and reforging cycles was reduced, and relatively uniform low-carbon steel was increasingly used directly to form the blade. Modern metallurgical analysis confirms that Sengoku-period kazuuchi-tou exhibit coarse steel microstructure indicating fewer forging cycles.

Standardized Form: A tachi form measuring approximately 2 shaku 3 sun (about 70 cm) in blade length became the standard, with workshops implementing assembly-line-like production of swords meeting uniform specifications.

Omitted or Forged Signatures: The market became flooded with "counterfeits" bearing famous smiths' names without authorization and unsigned mass-produced items. Kazuuchi bearing the signature of the Bizen Osafune school became known as "mass-produced Osafune" and were problematic even at the time, later becoming a major issue in sword authentication.

The "group signature system" symbolizes the signature problem at Bizen Osafune. The most popular signature, that of Sukesada, was reportedly shared by over fifty sword makers belonging to the same workshop, and swords bearing this name circulated in quantities reaching tens of thousands during the Sengoku period alone. The estimated total production of swords by the entire Bizen production center during the Sengoku period exceeded one million, demonstrating the industrial scale of the Japanese sword industry at the time.

However, it would be incorrect to dismiss all kazuuchi as inferior products. In the workshops of skilled craftsmen, processes were rationalized while maintaining minimum quality standards, and even today, Sengoku-period kazuuchi receiving authentication certificates (Preservation or Special Preservation grade) are not uncommon.

The Rise of Regional Sword Makers—The Dispersal of the Five Traditions

Another major change in the Muromachi and Sengoku periods was the dispersal of sword makers from their concentrated bases in the Kinai region and Bizen to all corners of the country. Regional daimyo independently recruited or trained sword makers, seeking to establish self-sufficient production systems within their domains.

Mino Province (present-day Seki, Gifu Prefecture) exemplifies this trend. Sword makers who had relocated during the late Kamakura and Northern and Southern Courts periods established themselves around Seki, and following the Ōnin War rapidly expanded their influence as a Mino school of sword makers. Blades produced by Kanemoto and Kanesada—known by the epithet "Seki's Magoroku"—were prized by Sengoku warlords for their strength and practicality, and "Mino blades" circulated throughout the nation.

In Satsuma (Kagoshima Prefecture), the Namihira school maintained continuity under the patronage of the Shimazu clan, and in the Northeast, the Date clan employed sword makers, establishing the tradition of "Sendai swords."

Bizen and Yamashiro—Fierce Competition Between Two Major Production Centers

Throughout the Muromachi period, two sword-making centers dominated sword production: the Osafune school of Bizen Province (present-day Setouchi, Okayama Prefecture) and sword makers descended from the Awataguichi and Rai schools of Yamashiro Province (Kyoto Prefecture).

Bizen Osafune had been the largest sword production center since the Kamakura period, and during the Muromachi period, a single school reportedly concentrated over several dozen to more than a hundred sword makers. A highly organized production system was established, encompassing raw material procurement, shared smithing tools, and sales networks, earning "Bizen blades" the highest reputation with brisk domestic and export trade.

Kazuuchi typically ranged in price from several hundred to several thousand mon, equivalent in modern terms to approximately 80,000 to 300,000 yen. This affordability—just a fraction of a master craftsman's commissioned work—provided the economic foundation enabling widespread adoption from foot soldiers to rural samurai. In the Mino production region, demand extended beyond tachi to polearms such as spears and naginata, and Seki smiths also established firm positions in polearm production.

In contrast, Yamashiro sword makers, as official smiths to the Muromachi shogunate, produced high-quality commissioned blades known as "jousaku" (上作) for the shogun's household and powerful daimyo. Though limited in quantity, each blade achieved high completion, and even today "Yamashiro blades" receive high evaluation from sword collectors.

However, following the Ōnin War, as Kyoto became a battlefield and Yamashiro workshops suffered devastating damage, Bizen's overwhelming mass-production capacity came to dominate the Sengoku market. The Sengoku period became an era marked by tension between quality and quantity in the sword industry.

What Sengoku Warlords Sought in Swords—Between Utility and Art

What Sengoku warlords sought in swords was not uniform. For those prioritizing actual combat, a sword's absolute requirement was to "neither break nor bend, and cut well." Even sword enthusiasts such as Oda Nobunaga and Tokugawa Ieyasu clearly distinguished between practical combat swords and fine blades kept for appreciation.

Critical to sword value assessment was the grading system of cutting ability designated as "wazamono" (業物), "ōwazamono" (大業物), and "saijō-ōwazamono" (最上大業物). The *Kaihou Kennjaku* (*懐宝剣尺*), compiled by Yamada Asaemon and published in 1797 (Kansei 9), systematized this, but the culture of cutting-ability evaluation underlying it was formed during the Sengoku period.

Aesthetic value regained prominence only following unification, from the Azuchi-Momoyama period (late 16th century) onward. When Toyotomi Hideyoshi launched a famous-blade collection movement called "meibatsu-gari" (名物狩り), and prestigious blades became objects of exchange among daimyo, swords again came to foreground their roles as status symbols and works of art.

The kazuuchi born from Muromachi warfare might be called the "shadow history" of the Japanese sword, yet without them, the brilliance of the blades held by the realm's unifiers would not have shone. The tension between mass production and artistic pursuit shaped the richness of Japanese sword culture—that legacy is quietly inscribed in each blade that TOUKENZA handles today.