Katana unsigned attributed to a work of Rai KUNIYUKI

Koto Middle of Kamakura period (Kougen era/circa 1256) Yamashiro
Length of cutting edge 73.6cm Curvature 2.2cm Width of base 29.1mm Width of Yokote 20.5mm Thickness of base 7.0mm


Polish and Sayagaki written by Ono Koukei (living national treasure) 


Sugata(configuration) : Shinogi-zukuri, Iori-mune. Osuriage substantially shortened. Rather on deeper side highly defined curve like an arch to a Shinto shrine standing firmly near the base, holding less degree of tapering from base to Ikubi-style Chu-kissaki.(click HERE for the high resolution image)
Kitae(forging pattern) : Kitae is Ko-Itame (fine wooden grain), mixing with large Itame-hada wares. Sparkling hard metal granules of Ji-nie appears that gives off diffused reflection with mottled effect so called "Rai-Utsuri".
Hamon(tempering pattern) : Hamon is Ko-nie a bit on stronger side Nie based, wide undulating Notare line with delicate small Gunome, small clove outline of Choji. Deep sparkling Nie accumulates on boundary line where long or short Nie lines of Kinsen and Sunagashi and slanting downward Kyo-saka-ashi appears.
The interior of hamon is filled with limpid Nioi that comes from abundant activities of forging and quenching using carefully selected different element of fine steel.
Boshi (tip): Boshi forms minutely irregular small circle turns back shortly.
Nakago(tang) : The tang is substantially shortened O-suriage. Two Mekugi-ana retaining holes. Slightly leftward file marks Katte-sagari.The heel shape is shallow Kurijiri double-bevelled.

The subject tachi created in an archaic style is attributed to a work of Rai-KUNIYUKI 来国行 from mid-Kamakura period period 13th C. He is the substantial founder of Rai school.
Although Nakago was substantially shortened to be an O-suriage, it stands firmly on base, still holds a highly defined curve like an arch, generous curved - unrestricted shape with a medium Kissaki so called Ikubi-style is a clear statement of it's age from mid-Kamakura period.
Forging that comes from carefully selected fine steel under Yamashiro Rai-school tradition generates Rai-Utsuri mottled reflection like a mist hung over the forest.
Hamon of founder KUNIYUKI is rather flamboyant small Choji-midare like this example unlike in the works of later generations of Rai-school. Boundary line is vividly clear in a bit on strong side of Ko-Nie and luminous Ji-nie with mottled effect Rai-Utsuri covers vividly on Hiraji.
Superb polish by Ono Koukei 小野光敬 / Condition scale: very good (using a scale of mint-excellent-very good-good-fair-poor)
The own hand writing Sayagaki mentions that this katana was elaborately polished in 1989 by a living national treasure Ono Koukei 小野光敬 (1913-94).
Gold foiled double layer Habaki collar, preserved in a Shirasaya. (
Sayagaki written by Ono Koukei 小野光敬)
reference : Honma Junji/Sato Kan'ichi, Nihonto Taikan, Otsuka Kogei-sha, 1968