Aoe Naotsugi

Aoe Naotsugi was a swordsmith who was active in the Aoe area of Bitchū Province (present-day western Okayama Prefecture) from the late Kamakura period through the Nanboku-chō period, and is one of the master smiths of the Aoe school. The Aoe school is a group of swordsmiths whose birthplace was Bitchū Province. While influenced by both the Bizen-den and Yamato-den traditions, it developed a distinctive texture of jitetsu (ground steel), making it an extremely individual school in the history of Japanese swords.

The greatest feature of Naotsugi's blades lies in the jitetsu expression unique to the Aoe school, which is also called "sumi-hada" or "chirimen-hada." Fine ko-itame is densely packed, and fine ji-nie spreads over the whole surface like haze, so the jitetsu of the blade body gives off a distinctive moist luster. This texture has long been praised in the world of sword appraisal as 'Aoe clarity' (Aoe no sumi), and it is prized as an aesthetic value unique to Aoe that other schools cannot easily reproduce. The hamon is mainly hoso-suguha or ko-midare, and shows a distinctive nioiguchi in which fine nie are densely arranged along the cutting edge.

Naotsugi's best-known masterpieces are a tachi inscribed with the date Kenmu 2 (1335), which, together with a naginata bearing the date Ryakuō 5 (1342), has been designated as an Important Cultural Property. This tachi displays a well-balanced form from the late Kamakura period into the early Nanboku-chō period, and the combination of the clear beauty of its jitetsu with a gentle suguha embodies the spirit of an age that was moving away from court culture. Its balance of blade length, curvature, and thickness (kasane) also reflects the ideal sword style of the time, and it is a valuable primary source for studying the stylistic evolution of Japanese swords from the late Kamakura to Nanboku-chō periods.

Aoe in Bitchū Province, where Naotsugi was active, is located in present-day Kurashiki (Okayama Prefecture). In this place, where high-quality iron sand and abundant fuel could be obtained, the Aoe school nurtured its own forging culture.

The techniques of the Aoe school continued to be passed down after Naotsugi, and several outstanding swordsmiths emerged, including Tsugunao, Moritsugu, and Sadatsugu. The representative signed work (an Important Cultural Property, 'Tachi, signed "Made by Sahyōe no jō Naotsugi, resident of Bitchū Province"') is held by the Kyoto National Museum.