This is a “Tosa Naoto” Bunka Japanese kitchen knife, manufactured by Hokiyama Cutlery in Kochi Prefecture, Japan, a region with a long and distinguished tradition of Tosa cutlery production.

The core steel is Aogami #1 (Blue Paper #1 / Blue #1 Steel), a premium Japanese high-carbon steel originally developed by Hitachi Metals (now Proterial). The reverse side of the blade is clearly stamped “Ao-Ichi Hagane” (青一鋼), identifying the core material as Blue #1 Steel.

Aogami #1 is a high-carbon steel alloyed with chromium and tungsten. When properly heat-treated, it is capable of taking an exceptionally keen edge while offering excellent edge retention and wear resistance. These characteristics have made Blue #1 a highly regarded steel for high-quality Japanese kitchen knives.

One of the most distinctive features of this knife is its beautiful multi-layer steel construction. Numerous flowing layers run along the lower portion of the blade, creating an organic, wave-like pattern. The layered steel develops subtle variations from blade to blade and contrasts beautifully with the darker upper portion of the blade.

The blade features a distinctive Bunka profile, combining a practical all-purpose blade shape with an angular K-tip. The pointed tip provides excellent control for detailed work, while the relatively tall blade offers good knuckle clearance and versatility for a wide range of kitchen tasks. The strong geometric silhouette also creates a striking contrast with the flowing pattern of the multi-layer steel.

The front of the blade bears the “Tosa Naoto Saku” (土佐 直斗作) inscription and maker’s mark, while the reverse is stamped “Ao-Ichi Hagane” (青一鋼 / Blue #1 Steel).

Manufactured in Kochi by Hokiyama Cutlery, this Bunka combines the cutting characteristics of premium Blue #1 carbon steel with the craftsmanship and distinctive visual beauty of multi-layer Japanese blade construction.

Made in Kochi, Japan