Hatsukokoro x Myojin Shirasagi Ginsan Deba 180mm

Yes, the bones of fish and fowl. Japanese dictionaries describe the deba (出刃包丁) as wide, thick-spined and heavy, used to fillet fish, to cut fish and fowl bone and all, and for rough chopping.

When you chop bone, use the heel of the blade (刃元), the Sakai cutlery association says. It is a fish and poultry knife, not a cleaver.

Ginsan steel, also known as Silver #3 or G3, is a stainless steel made by Proterial in Japan, containing 0.95 to 1.10% carbon and 13.00 to 14.50% chromium, and it is used in Japanese knives because it combines the sharpness and ease of sharpening of carbon steel with the rust resistance of stainless steel. It is a fine-grained steel that takes a very sharp edge, and rated by Proterial at over 59 HRC, it offers a practical balance of edge retention and sharpenability for everyday kitchen use.

The name "Ginsan" (銀三) literally means "silver three," referring to its Silver #3 designation. Its moderate chromium content makes it far less reactive than carbon steels, so it won't discolor or rust as quickly, while its carbon content keeps the edge keen and responsive on the stones. For home cooks and professionals who want a stainless knife that still feels like a traditional Japanese blade, Ginsan is a common middle ground.

Yes. Proterial lists the steel as GIN 3 (銀紙3号) with 13.00 to 14.50% chromium, above the Japan Stainless Steel Association's 10.5% minimum for stainless steel.

Proterial describes it as a stainless steel with hardness and sharpness comparable to carbon steel, used in various kitchen knives and scissors, and the association notes that stainless, strictly, means it rusts less. Wash the knife and dry it after use.

The Hatsukokoro Shirasagi Ginsan Kasumi line consists of single-bevel knives made from Ginsan stainless steel and sharpened at the Myojin Riki Seisakusho workshop in Kochi, designed primarily for professional chefs and enthusiasts who want a lower-maintenance alternative to carbon steel Debas.

The flat of the blade (Hira) is polished to a Migaki finish and the bevel has a contrasting misty Kasumi finish, with the scratches set in different directions to give a crisp Shinogi line. The blades may need some initial work on arrival. The line is positioned as a practical option for those needing a reliable Deba without the high upkeep of traditional carbon steels, offering a consistent level of fit and finish on the spine and corners.

If you are looking for a specific in-stock example, the Hatsukokoro x Myojin Shirasagi Ginsan Ko Deba 120mm is available at an entry-level price, while the larger Hatsukokoro x Myojin Shirasagi Ginsan Deba 180mm sits at the higher end of the range.

A hamaguri-ba edge, written 蛤刃, is a convex edge shape, and it is the shape the workshop 明神利器製作所 sharpens its knives to. Kochi City's craft page records that Myojin Riki learned it over several years of training in Fukui.

The same page says the workshop also takes sharpening-only orders from outside Kochi.

Yes. Kochi City's craft page for his workshop 明神利器製作所 says the work runs from forging through finishing in one continuous process, 鍛造から仕上げまで一貫して行う.

That page lists the workshop in Susaki, Kochi.