Myojin Riki Seisakusho COSP Bunka 180mm

At the heart of Japan’s knife-making tradition lies Myojin Riki Seisakusho, a workshop led by the talented sharpener Myojin Naohito and his Father Tateo Myojin in Kochi Prefecture. Known for his exceptional skill in bringing blades to life through precise sharpening, Myojin represents a new generation of Japanese craftsmen who carry forward the legacy of their ancestors while adapting to the needs of today’s kitchens.

Myojin is regarded as one of the most distinguished students of the legendary master sharpener Morihiro, whose guidance left a lasting impact on his craft. Morihiro’s influence is evident in Myojin’s work today — with his blades recognized for their flawless, consistent grinds and the graceful Mount Fuji–shaped spine that has become his hallmark.

In his younger years, Myojin also trained briefly as a blacksmith, gaining valuable insight into the forging process before returning to his roots in sharpening. Reuniting with his father, Tateo Myojin, he went on to establish Myojin Riki Seisakusho, a workshop that continues the family’s legacy through a signature line of knives crafted with SG2 steel — uniting tradition, precision, and modern performance.

What is COSP Steel?

According to Takefu, COSP is a stainless steel produced using a special secondary remelting process. This process creates an exceptionally uniform steel structure with an extremely fine dispersion of carbides throughout the material.

To put it simply, imagine molten steel being broken down into tiny droplets and rapidly cooled before being remelted. This rapid solidification prevents carbides from forming large clusters, resulting in a much finer and more consistent grain structure—similar in principle to why proper heat treatment improves steel performance, but achieved during the steelmaking process itself.

How does it compare?

• Think of COSP as sitting comfortably between VG10 and SG2.
• Compared to VG10, COSP offers finer grain, easier sharpening, and noticeably better edge retention.
• Compared to SG2, COSP is generally easier to sharpen and tougher, although SG2 still holds an edge for longer due to its higher volume of hard carbides.

Origin : Susaki , Kochi Prefecture, Japan

Brand: Myojin Riki Seisakusho

Knife Type: Bunka

Sharpener : Naohito Myojin （明神 直人）

Blade Construction: Sanmai

Grind: Double-edged Blade (50/50 Grind)

Hagane (Core Steel): COSP ( Cobalt Special ) 

Jigane (Cladding): Stainless steel

Hardness: 62 HRC

Blade Finishes : Kasumi Polish

Blade Length : 180mm

Blade Height (at heel): 47mm

Spine Thickness Above heel: 2.0 mm

Spien Thickness At Tip : 1.8 mm 

Weight : 130g

Handle Shape: Octagonal Ebony Wood

Hand Chiseled Mark : In Japanese Kanji ( 直人作）Naohito Made

**Care Instructions:**  

To maintain COSP knives, it’s essential to hand wash them with mild soap and water, then immediately dry them to prevent water spots or potential corrosion. Avoid cutting on hard surfaces like glass or granite, and store the knife in a sheath or on a magnetic strip to protect the blade.To maintain the blade’s edge and its lifespan, avoid chopping it on bones and frozen foods. 

Please note that the edge may appear black due to the photography lighting, but it is not actually black.