Aoe Tsunetsugu

The Singular Brilliance of Bitchū — The Aoe School and the World of Tsunetsugu

Aoe Tsunetsugu was a swordsmith active in the early Kamakura period in the Aoe district of Bitchū Province (today the western part of Okayama Prefecture), and he is recorded in the history of the Japanese sword as a leading master of the Aoe school. Bitchū Province lies directly west of Bizen Province and, since ancient times, has been a favorable place for sword production, blessed with high-quality iron sand and abundant charcoal. The Aoe school arose here in the late Heian period and flourished in the Kamakura period.

Aoe Tsunetsugu is considered to have been one of the bankaji (attending smiths) of Emperor Go-Toba, and he is thought to have been active in the early Kamakura period. Works of Koaoe (Old Aoe) bear no era name in their signatures. Working at the same time as the smiths of Kobizen (Old Bizen) and the Ichimonji school of Bizen Province, he opened a path of his own with a completely different style, and this contrast makes the appeal of Aoe blades all the more striking.

The Mystery of Aoe-hada — The Beauty of the Clear Jigane

What is first cited as the greatest distinguishing feature of Aoe Tsunetsugu, and of the Aoe school as a whole, is the distinctive pattern of the steel surface known as “Aoe-hada.” At its heart is “sumihada,” in which dark patches called jifu appear within clear, bluish steel. The old transmitted texts describe it as “a blue ground in which the color of the iron changes and appears in places as dark spots,” a steel beauty unique to Bitchū Aoe.

In general, the jigane of Bizen blades shows reddish, healthy chikei, whereas Aoe-hada has a bluish, translucent clarity. This jigane, also called “sumihada,” leaves an unforgettable impression and is the most important indicator for identifying Bitchū Aoe in sword appraisal. The jinie is fine and evenly distributed, and the way fine silver-white grains shimmer across the bluish surface of the steel is as mysterious and beautiful as stars spread across the dawn sky.

Sakachōji — A Paradoxical Contrast with Bizen

Another distinctive feature of the Aoe school is its hamon, in which the feet of the chōji do not meet the edge at a right angle but slant diagonally, in what is described as a “reversed” (sakagatta) form. A chōji that has taken on this reversed form is called sakachōji.

Sakachōji has a visual sense of movement opposite to the regular chōji of Bizen. Whereas ordinary chōji rise from bottom to top, sakachōji descends from top to bottom as if following gravity, creating a sense of stability and weight. This visual heaviness, combined with the deep jigane of Aoe-hada, gives the blades of Aoe Tsunetsugu a distinctive, calm dignity.

The hamon of Koaoe is mostly suguha or ko-midare, with many examples including small chōji, and it varies from work to work. As a general tendency of Aoe hamon, however, the base is a somewhat small and calm midare, quite different from the splendid chōji midare of Bizen blades.

The Form of the Tachi — The Typical Beauty of Koaoe

The form of Aoe Tsunetsugu's tachi shows the typical shape of a Koaoe tachi. The Koaoe tachi has a strong curvature in the lower part of the blade (koshi-zori), and from the base (moto) toward the tip the curvature becomes shallower and the width narrower, ending in a small kissaki. This is its characteristic feature.

A feature of Koaoe is that the file marks on the tang (nakago) are ō-sujikai, and that even among tachi, many bear signatures cut on the reverse side of the tang (ura-mei).

The Lineage of the Aoe School — Tradition Across the Ages

From Koaoe emerged many excellent smiths besides Tsunetsugu, including Sadatsugu, Tsugu'ie, Tametsugu and Yasutsugu. The lineage of the Aoe school begins with Koaoe in the late Heian period, passes through Chūaoe (Middle Aoe) in the late Kamakura period, and continues into Sueaoe (Late Aoe) in the Nanboku-chō period.

Within this lineage, Tsunetsugu is held in particularly high regard as a representative master of Koaoe. The “Kanchi-in-bon Meizukushi” records that he, together with Sadatsugu and Tsugu'ie, was summoned to serve as a bankaji of Go-Toba-in. In the later Sueaoe, smiths such as Tsuguyoshi and Tsugunao are known, and styles changed greatly, with great tachi over three shaku in cutting length and large-patterned chōji midare with reversed features appearing.

Surviving Works of Tsunetsugu — Academic Significance

Among the surviving works of Aoe Tsunetsugu are the “Juzumaru,” one of the Five Swords of Heaven (Tenka Goken), held by Honkō-ji in Hyōgo, as well as tachi designated as Important Cultural Properties, such as those in the collections of Kitano Tenmangū and the Tsuchiura City Museum. They are widely known as outstanding examples representing Koaoe.

Signed works by Tsunetsugu are relatively numerous, but a certain number of works are also attributed to him through mumei kiwame (appraisal of unsigned blades). The features of Aoe-hada and sakachōji serve as the principal criteria in appraisal.

Tsunetsugu's Spirit and the Tōken-za

The “tranquil beauty of sumihada and sakachōji” displayed in the blades of Aoe Tsunetsugu embodies a third aesthetic, entirely different from the Bizen blades that win through splendor and the Sōshū blades that overwhelm with strength. This beauty is quiet and profound. Like a clear mountain stream far from the clamor of the world, it can only be truly understood when the viewer faces it slowly, over time.

The Tōken-za respects the splendor of Bizen blades, but it also treasures the tranquil beauty embodied by Aoe Tsunetsugu as an important aspect of the world of the Japanese sword. A blade of Aoe Tsunetsugu, “where sakachōji flows across bluish jigane,” is one of the works that best reveals the depth of the art of the Japanese sword, and the Tōken-za hopes that every sword enthusiast will come to know it.