Mitsuo Yamatsuka

Mitsuo Yamatsuka (山塚光雄) is a knife sharpener (研ぎ師) based in Sakai, Osaka, Japan. He is a certified Traditional Craftsman (伝統工芸士) in the Sakai forged-blade craft (堺打刃物), a national designation he has held since FY1999. He sharpens and finishes blades for the Sakai Takayuki brand (Aoki Hamono).

He has worked in the craft since 1973 and is still actively sharpening today.

Mitsuo Yamatsuka is known for sharpening and finishing knife blades (研ぎ). His registered signature technique is kasumi (カスミ研ぎ), a hazy polish, and his stated specialty covers single-bevel, mirror, and double-bevel sharpening (片刃・鏡面・両刃研ぎ).

He was certified a national Traditional Craftsman (伝統工芸士) in the Sakai forged-blade trade in FY1999. In FY2015 the City of Sakai also named him a certified Meister (堺市ものづくりマイスター) in its knife-making (edge-setting) trade, recognizing his single-bevel (片刃) kasumi sharpening and finishing.

Mitsuo Yamatsuka is based in Sakai, Osaka, Japan. He works in the Sakai forged-blade craft (堺打刃物), the trade under which the national craftsman registry records him. From there he sharpens and finishes blades for the Sakai Takayuki brand (Aoki Hamono).

Mitsuo Yamatsuka is a knife sharpener and finisher (研ぎ師), not a blacksmith. There is a separate Yamatsuka blacksmith lineage in Sakai (the smiths 山塚拓志 and 山塚尚剛, who trained in a forging family).

Yes. Mitsuo Yamatsuka is still actively sharpening. He continues to stand at the sharpening station and is passing his craft to his two sons, who are both sharpeners.

In 2025 he also worked as a knife-sharpening demonstrator and serves on the Traditional Craftsman certification examination committee (試験委員).