Minamoto Kanemasa "B-Series" Shirogami #3 Kurouchi Kasumi Mioroshi-Deba

by Seki Kanetsune


Mioroshi-Deba is the knife to go when you needed something that is sharp for cutting, long for slicing and tough enough to get through small fish bones. In the bustling Tsukiji market, fish wholesalers do not have the luxury of switching knives all the time, and Mioroshi-Deba is the one knife to go. Hand-forged using Shirogami #3 high carbon steel as core, cladded with soft iron, this knife is specially designed for serious professionals who handle larger fish. For right-handed use.


  • Origin (Made in): Seki, Gifu Prefecture, Japan
  • Brand: Minamoto Kanemasa (part of Kanetsune Seki)
  • Knife Type: Mioroshi-Deba
  • Blade
    • Construction: Awase (Kasumi)
    • Grind: Single Bevel (Right-handed)
    • Hagane (Core Steel): Shirogami #3 (White #3)
    • Jigane (Cladding): Soft Iron
    • Hardness: 60-61 HRC
    • Hand-forged, hand-grinded, hand-sharpened
  • Blade Finishes:
    • Kasumi Polish
    • Kurouchi
  • Blade Length: 210mm (8.3") / 240mm (9.4")
  • Blade Height (at heel): 42mm / 47mm
  • Spine Thickness
    • Above heel: 5.9mm / 6.2mm
    • Middle: 4.9mm / 5.6mm
  • Handle
    • Shape: Marugata (Oval-shaped)
    • Material: Japanese Magnolia (Ho Wood)
    • Length: 135mm / 142mm
  • Overall Length: 364mm / 396mm
  • Weight: 287g (5.04oz) / 336g (11.85oz)
  • Hand Chiseled Mark: In Japanese Kanji "Kanemasa Made" (兼正作)

About Kanetsune Seki 関兼常 / Kitasho 北正

The owner of Kanetsune Seki brand — Kitasho — has been making knives in pre-war Japan, in Seki City (関市) which has over 800 years of blade-making history. After the war, they established the Kitamura Shoten, which led to the current Kitasho company. The Kanetsune (兼常) brand is named after a famous sword-smith who lived in the Muromachi period around 14-15 century. Making different series of knives under brands including Kanemasa (兼正作), Honsho Kanemasa (本匠兼正作), and Minamoto Kanemasa (源兼正), Kitasho Company is on the mission of passing down Seki’s 8 centuries long knife-making techniques and traditions.


Shirogami #3 (white #3) steel is one of the popular types of high carbon steel found in Japanese kitchen knives (Wa Knives). It is not stainless, therefore you must wipe your knife dry after each use. Patina will develop over time. Rust may develop if left in prolonged contact with water or acidic food. Use a rust eraser to clean if rusts develop. Avoid cutting into bones, frozen foods, hard fruit pits.

Cutting Surface:

Recommended cutting surface: wood, rubberized boards and high-end composites, and quality plastics such as polyethene make acceptable cutting surfaces, and will help protect and prolong knife’s edge. AVOID glass, metal, countertops, and other rigid, non-forgiving surfaces.


We recommend sharpening all quality Japanese knives on whetstones, as we believe they yield the best results for your knives.

Free Shipping

Free Shipping on most orders.

30 Days Return

Return unused within 30 days for a full refund, no questions asked (terms apply).

Top Japanese Makers

All knives made in Japan by top Japanese knife makers.