Ko-Hōki Aritsuna

Ko-Hōki Aritsuna was a swordsmith active in Hōki Province (present-day Tottori Prefecture) from the late Heian period into the early Kamakura period. He is one of the important smiths of the Ko-Hōki school, which continues the lineage of Hōki Yasutsuna, renowned as the progenitor of the origins of nihontō. The Ko-Hōki school formed a lineage with Yasutsuna as its founder, followed by Sanemori, Aritsuna and Sadatsuna. It was a group of smiths who carried the earliest phase of Japanese sword forging, rooted in the iron-making tradition unique to the San'in region.

Aritsuna's blades continue the technical lineage of the Ko-Hōki school while embodying the stylistic changes of the transition from the late Heian to the early Kamakura period. The jigane shows itame mixed with mokume-hada, with ji-nie and abundant chikei. Such jigane is the product of an ancient iron-making method using the abundant iron sand of the Chūgoku mountains, and it has an archaic character clearly distinct from blades made in other regions. The hamon is ko-midare with ko-gunome-like elements mixed in, with ashi appearing, and the habuchi carries coarse nie, while kinsuji and sunagashi work vigorously. The Ko-Hōki school's distinctive rough expression of nie strongly reflects the aesthetic of the transitional period from the late Heian to the early Kamakura period.

The taihai of the tachi shows funbari and a high koshi-zori, presenting a graceful form that resembles a treasure sword. The signature (mei) consists of the two characters 'Aritsuna', cut in an archaic script.

Signed works by Aritsuna are extremely rare, and few reliably extant examples survive. However, as a smith who holds an important position in the Ko-Hōki lineage, second only to Yasutsuna and Sanemori, the small number of transmitted examples have high cultural-property value as materials conveying the earliest stage of nihontō history. Among the extant works is a tachi designated as an Important Cultural Property, which is owned by the Tokyo Fuji Art Museum.