Late Muromachi to Sengoku (Late Kotou)

The Ōnin War and Kyoto

In 1467, the Ōnin War erupted, sparked by a conflict between the Hosokawa and Yamana clans—families of the shogunal deputies to the Muromachi shogunate—and Kyoto became scorched earth. Triggered by this great war, the authority of the Muromachi shogunate collapsed, and across the nation, constable-daimyo and local lords competed for hegemony, opening the Sengoku period. As the spirit of gekokujō spread and ashigaru of peasant origin became the main force in battles, demand shifted explosively from individual samurai swords to practical blades issued to large numbers of soldiers.

Large Blades Come into Vogue

It was two great production centers—Bizen Osafune and Seki in Mino—that answered this unprecedented demand. In Bizen Osafune, the Sukesada family flourished as the largest smith group, forging a wide range of qualities from mass-produced blades called 'tanged bundles'—tied together and sold by the bundle—to fine custom-forged pieces commissioned by daimyo and powerful warlords. Dozens of smiths bearing the Sukesada signature are said to have been active during the same period, and among them, Yosaemon-no-jō Sukesada and Hikobei-no-jō Sukesada left fine examples of custom-forged work. Katsumitsu was a renowned Late Bizen smith ranking alongside Sukesada, and collaborative works bearing both his and Munemitsu's names with dates are also known. From the Eishō era (1504–1521) through the Tembun era (1532–1555) was the golden age of Late Bizen, and during this period Bizen blades demonstrated overwhelming presence in both quality and quantity.

Smith Collectives

However, around 1590, a great flood of the Yoshii River struck the Osafune area, and many smiths' forges suffered catastrophic damage. As a result of this disaster, Bizen smithcraft rapidly declined, and its status as Japan's largest blade production center was ceded to Seki in Mino. The decline of Bizen Osafune was a major turning point in Japanese sword history and one of the indirect factors that prompted the transition from kotou (old swords) to shintou (new swords).

Regional Characteristics

In the Mino tradition, the Seki smith collectives achieved dramatic growth throughout the Sengoku period. At the peak of this was Mago Roku Kanemoto, renowned as 'Seki's Mago Roku.' Kanemoto originated a distinctive gunome-midare hamon called 'Three Cedar Trees,' characterized by three sharp, consecutive yaki lines, and gained the absolute confidence of warlords through its keen cutting ability. Izumi-no-Kami Kanesada is known by the alias 'Nosada,' a name derived from how he cut the radical in the character 定 in the shape of the character 之. Nosada blades demonstrated high standards in all respects—the forging of the jigane, the clarity of the hamon, and the balance of the sugata—and he became widely known as a representative master smith of Mino blades.

Technical Innovation

The most important change of this era was the complete transition from tachi to uchigatana. Whereas the tachi was worn hung from the waist with the edge facing down, the uchigatana was worn thrust through the belt with the edge facing up. This change in wearing method had the advantage of allowing the draw and cut to be performed in a single motion, making it well-suited to the quick decisive tactics centered on ashigaru. A practical blade length of around two shaku two sun (approximately 66 centimeters) became established, and lightweight designs that could be wielded with one hand were demanded. Thus, the form of the uchigatana established during the Sengoku period is the very form that we in modern times recognize as the 'Japanese sword.'

The Move to the Sengoku Age

Responding to the demands of Sengoku daimyo, provincial smiths in various regions became increasingly active. In Satsuma, the Namihira school forged swords for the Shimazu clan, and in Higo, Dōtanuki Massakuni, as the official smith of Katō Kiyomasa, mass-produced robust, practical combat blades. The emergence of distinctive smiths in various regions—such as Shimada Yoshisuke of Suruga, Chiyozuru Kuniyasu of Echizen, and Tanaka Kunihiro (later known as Horikawa Kunihiro) of Hyuga—was also an important characteristic of the Late Kotou period.

Late Kotou blades exhibit an extremely wide range of quality, from mass-produced pieces to custom-forged commissions. While mass-produced pieces have rough signatures and simple construction, the fine examples of custom-forged work often embody the traditions of kotou, and custom-forged pieces by Kanemoto, Kanesada, and Sukesada especially enjoy enduring popularity among collectors. Many blades are connected to anecdotes of Sengoku warlords, and Late Kotou, which combine historical allure with the aesthetics of practical utility, represent a genre through which collectors can truly savor the essence of Japanese sword collecting.