Rai Kunitsugu

Rai Kunitsugu was a swordsmith of the Rai school based in Kyoto in Yamashiro Province, and is said to have been active from the late Kamakura period into the early Nanboku-chō period. He is said to have been a disciple of Rai Kunitoshi, and a later theory holds that he was a son or pupil of Rai Kunimitsu. Various traditions exist regarding his lineage. The Rai school began with Rai Kuniyuki in the mid-Kamakura period and produced Rai Kunitoshi, Rai Kunimitsu, and others, forming a lineage that represents the Yamashiro tradition. Within that school, Rai Kunitsugu is known as a distinctive presence. According to tradition, Kunitsugu moved to Kamakura in Sagami Province and studied under Masamune, and there is a theory that he is listed as one of the Masamune Juttetsu (Ten Great Disciples of Masamune), the leading pupils of Masamune. For this reason he is also called Kamakura Rai, and he is positioned as a swordsmith who bridged the Yamashiro Rai school and the Sōshū tradition.

Rai Kunitsugu's style is characterized by retaining the fine, precise qualities of the original Rai school while strongly reflecting the influence of the Sōshū tradition. The Rai school typically shows ko-itame hada, tightly packed, with fine ji-nie across the surface and, here and there, a forging texture known as Rai-hada. Kunitsugu, in addition to this, has a jigane with raised hada, with chikei well entering, and with strong nie appearing in both the jigane and the hamon. Unlike the calm, straight-hamon (suguha-style) works common to the Rai school, his hamon is a nie-deki midare hamon: ko-notare mixed with gunome, with ashi and yō well entering, nioi deep with fine nie, and sunagashi and kinsuji falling here and there. A style with such conspicuous chikei, kinsuji, and sunagashi is clearly in the Sōshū tradition manner and differs in character from works of the purely Rai school.

In this way, Rai Kunitsugu is evaluated as an unusual swordsmith who, within the Yamashiro Rai school, shows the style closest to the Sōshū tradition. Of his extant signed works, tantō and wakizashi make up most, and signed tachi are very few. Many of the finest works are tantō, and tachi are said to be few in number with few worthy examples, so his specialty in tantō sets him apart from other swordsmiths of the Rai school.

The most celebrated of his representative works is the tantō signed Rai Kunitsugu (privately owned), designated a National Treasure. It has a hira-zukuri form with a mitsu-mune, a wide body, and a slight curvature, and its body length is approximately 32.7 centimeters. The forging is ko-itame hada, well packed, with slight Rai-hada appearing on both the front and back, ji-nie and chikei present, and a crisp jigane. The hamon is ko-notare mixed with gunome, with ashi and yō well entering, nioi deep with fine nie, and sunagashi and kinsuji falling here and there, making a striking work that clearly shows the influence of the Sōshū tradition. Beyond this, several signed works are known, including two tachi designated Important Cultural Property, and they are highly valued as jōsaku.