The Kakitsu Rebellion (1441) and the Sword Industry: How the Assassination of Ashikaga Yoshinori Transformed the Muromachi Blade Market

The Kakitsu Incident: What It Was

In the sixth month of Kakitsu 1 (July 1441), Akamatsu Mitsusuke, daimyo guardian of Harima, Bizen, and Mimasaka, invited the sixth shogun Ashikaga Yoshinori to his residence in Kyoto and assassinated him during a banquet. This was the "Kakitsu Incident." Yoshinori was known for his despotic exercise of power, having pressured many daimyo and temple-shrine forces, so his death was widely received as a kind of "liberation." However, the political vacuum immediately brought deteriorating security and frequent armed conflicts, causing dramatic shifts in sword demand.

Sword Market Fluctuations Born from Political Vacuum

In the mid-Muromachi period when shogunal power temporarily collapsed, daimyo began competing for military superiority against one another. Though the Akamatsu clan was destroyed by the shogunate army's pursuit, armed conflicts intensified around Harima and Bizen during this process, and demand for equipment replacement surged. According to historical records, in the 10 years following the Kakitsu Incident, the number of registered swordsmiths in the Osafune area of Bizen increased by approximately 30% (historical estimates).

The surge in demand also affected sword quality control. As daimyo retainers rushed to equip themselves, workshops capable of delivering large numbers of swords in a short time were favored. This "shift toward mass production" became one factor forming the foundation of mass-production sword culture on the eve of the Ōnin War (1467).

Regional Responses: Bizen, Mino, and Yamato

Bizen (Osafune): The Osafune smith collective had established an organized division-of-labor system since the Kamakura period and could respond relatively smoothly to increased demand after the Kakitsu Incident. During this period, the Osafune Morimitsu and Yasumitsu workshop lineages bore the core of supply, with the transition progressing from the "Ōei-form" with suppressed curvature to practical-combat-focused forms.

Mino (Seki): Seki smiths, supported by the Mino daimyo Toki clan, strengthened supply to samurai in the Tokai and Kanto regions. In particular, demand increased for single-edged, lightweight uchi-katana, and Seki's "practical swords" became widely popular among lower-ranking samurai. The surge in demand during this period became the foundation for later establishing mass-production techniques in the Mino tradition.

Yamato (Nara): Yamato smiths had strong ties to temple-shrine forces and, even amid political instability following the Kakitsu Incident, were protected by powerful institutions such as Kofuku-ji and Kasuga Taisha. Demand for dedication swords and ceremonial swords remained relatively stable, and Yamato tradition's delicate suguha technique continued unchanged.

Changes in Sword Distribution and Consignment Sales

Another impact the Kakitsu Incident had on the sword industry was a change in distribution routes. The practice of shogunal sword gifts and dedications—previously directly managed—temporarily became dysfunctional, and daimyo began establishing their own procurement routes. During this period, sword merchants (tou-ya) began visiting daimyo residences and castles for direct transactions, forming "authorized merchant" type relationships.

Furthermore, the confiscation of swords in parts of Harima and Bizen following the Akamatsu clan's collapse resulted in increased secondhand sword circulation in the secondary market. The relaxation of the shogunate-controlled meibotsu system and increased commodification of swords in the market represented another facet of this period's industry structural changes.

The Historical Significance of the Kakitsu Incident in Sword History

The Kakitsu Incident was not merely a political coup but also a turning point in mid-Muromachi sword industry restructuring. The shift from reliance on shogunal authority to a sword market led by daimyo and local samurai, the reversal from mass-production to quality-focused approaches, and the diversification of distribution routes—these changes accumulated over approximately 30 years leading to the Ōnin War and underpinned the transformation of Japanese swords from "exclusive domain of the warrior class" to "widely circulated commodities."

Understanding this era provides crucial context for accurately reading the relationship between manufacturing background and quality when appreciating and collecting mid-Muromachi swords. In swords from after Kakitsu, the traces of political upheaval are inscribed in the steel.