Sword Culture of the Muromachi Period: Mass Production and Practicalization Born from the Onin War

Overview and Historical Position of the Muromachi Period in Japanese Sword History

The Muromachi period (1336–1573) marks an era when the Ashikaga shogunate established their government in Muromachi, Kyoto. From a sword history perspective, it is often positioned as a "transitional period." This era witnessed the shift from the highly artistic tachi of the Kamakura period to the practical uchigatana of the Sengoku period.

The Muromachi period can be subdivided as follows:

• Nanboku-chō Period (1336–1392): Long swords from the previous era (such as the "Shizu Saburō Kanesada" of the Enbunn and Teiji eras) dominated
• Early to Mid-Muromachi (1392–1467): In times of peace, smaller swords became fashionable. Tantō and short wakizashi proliferated
• After the Ōnin and Bunmei War (1467–): An age of gekokujō. Practical uchigatana rapidly spread throughout society

Swords of the Nanboku-chō Period—The Age of Large Tachi and Wild Tachi

The beginning of the Muromachi period coincides with the upheaval of the Nanboku-chō civil war. Swords from this period, known as ōdachi (large tachi) and nodachi (wild tachi), were exceptionally long. Many blades exceeded 2 shaku 7 sun (approximately 82 cm) and developed as two-handed "cutting weapons" wielded by ashigaru on the battlefield.

Representative swordsmiths of the Nanboku-chō period:

• Shizu Saburō Kanesada: A Sōshū technique artisan who transmitted the Sōshū school to Mino province, known for the bold irregular hamon of Sōshū style
• Hasebe Kunishige: A Yamashiro swordsmith who inherited Sōshū techniques
• Kaneshige and other Bizen smiths: In Bizen, centered around Osafune, numerous long tachi were produced

Many swords from this era underwent suriage (shortening through polishing) in later years, and often exist in a state of reduced original length.

The Ōnin War (1467)—A Turning Point in Sword Culture

The greatest turning point in Muromachi sword history is the Ōnin War, which erupted in 1467. Lasting eleven years and ravaging Kyoto as a battleground, the conflict spread nationwide and marked the beginning of the "Sengoku period."

Impact of the Ōnin War on sword culture:

1. Sudden surge in demand for swords: The widespread conflict required vast numbers of combatants—samurai, ashigaru, peasants, and more. This sparked an unprecedented surge in sword demand, far exceeding what individual smiths producing in small quantities could supply.

2. Establishment of mass production systems: To meet demand, swordsmiths from Bizen (Okayama Prefecture) organized systematic mass production. The Bizen swords of this period, called suebizen, became known for being produced efficiently while maintaining high technical standards. Signatures of smiths such as Osafune, Ishidō, Kiyomitsu, and Tadamitsu remain abundant, and these blades circulate relatively widely even today, centuries later.

3. Rise of the uchigatana: Seeking ease of use in combat, the uchigatana rapidly became dominant. Whereas the tachi was worn with the cutting edge downward in a haitō style suspended from the waist, the uchigatana was worn with the cutting edge upward in a sashikata style inserted into the belt. With its quick, efficient draw, the uchigatana surpassed the tachi as the primary close-combat weapon.

Structural Characteristics of the Uchigatana—Differences from the Tachi

The uchigatana, which became standard in the late Muromachi period, differed from earlier tachi in the following ways:

This transformation deeply reflects the era's spirit of gekokujō. The shift from the tachi—a weapon for mounted samurai—to the uchigatana, a weapon for ashigaru fighting on foot, reveals how sword design mirrored tactical evolution.

Wakizashi and Kodachi—Weapons for Daily Carry

By the late Muromachi period, the custom of carrying a daisho—a set of a tachi and wakizashi together—began to generalize among samurai. The wakizashi, with a blade length between 1 shaku and less than 2 shaku, was carried alongside the primary uchigatana. Bearing both became the formal dress of a warrior (the institutionalization of the daisho system came later in the Edo period).

Demand also grew for kodachi and tantō—weapons portable by peasants, merchants, and craftspeople alike—accelerating the proliferation of arms across social classes. This social background would eventually necessitate the "katanagari," the sword hunt ordered by Toyotomi Hideyoshi in 1588.

Rise of Mino Swordsmiths—Establishment of Seki's Reputation

In Muromachi sword history, the ascendance of swordsmiths from Mino province (present-day Gifu Prefecture) cannot be overlooked. In particular, the town of Seki flourished as a metalworking center, blessed with abundant quality charcoal and excellent water transport, establishing the name "Seki blades."

Characteristics of Mino-den:

• Kanesada and Kanemoto of the "Magorokku Kanemoto" lineage: A celebrated master known as "two-character signature Kanemoto"
• Sanbon-sugi hamon: A distinctive Mino-style hamon featuring groups of three interlocking notches arranged side by side
• Adoption of kiriage-zukuri: Mino smiths excelled in this style, prioritizing practical function for battlefield use

Mino swords of the Muromachi period became favorites of later Sengoku warlords, and notable figures such as Oda Nobunaga and Toyotomi Hideyoshi were known to favor blades produced at Seki.

The Muromachi period stands as a transformative age in which the Japanese sword fundamentally shifted from "art object to practical weapon." The rich sword culture of this era—a mixture of mass-produced blades and masterpieces—remains a vital focus of modern Japanese sword scholarship.