Takayuki Shibata works near Fukuyama City in Hiroshima Prefecture, and his Koutetsu line has earned a serious following among cooks who prioritize cutting feel above almost everything else. The name Koutetsu, meaning ironclad, references the first ironclad warship in Japan - a fitting metaphor for blades built on advanced materials and precise engineering rather than traditional aesthetics. Shibata-san is known specifically for his heat treatment, his sharpening, and a grind geometry that consistently produces one of the thinnest, most effortless cutting experiences available at any price.
The Boss Bunka is an oversized take on the bunka profile, stretching to 225mm blade length and 59mm tall - tall enough to function as a tall nakiri, long enough to handle proteins and longer slicing runs, with the sharply defined k-tip that makes the bunka format so useful for precision detail work. The R-2, also known as SG2, powdered stainless steel core is hammer forged in a san mai construction and hardened to approximately 62-63 HRC. That hardness is what allows the kasumi finish grind to run as thin as it does without sacrificing edge stability - the spine is just 2mm at the base, and the blade is ground to a double 50/50 bevel that produces minimal wedging through dense produce. The octagonal rosewood handle keeps the whole package light and balanced for extended prep sessions.
Care Instructions: R2/SG2 powdered stainless is highly stain-resistant but hard and chip-prone at high HRC. Hand wash and dry after use - avoid the dishwasher. Use wood or rubber cutting boards only - avoid bones, frozen foods, and hard materials. Strop regularly between sharpenings and use a consistent angle and light pressure at the stone to maintain the acute edge geometry.Blacksmith: Takayuki Shibata
Location: Fukuyama City, Hiroshima, Japan
Construction: San Mai, Hammer Forged
Edge Steel: R2/SG2 Powdered Stainless
HRC: 62-63
Cladding: Stainless
Edge Grind: Even (50/50)
Handle: Octagonal Rosewood
Ferrule: Black Pakka Wood
Weight: 6.2 oz (178 g)
Blade Length: 225 mm
Total Length: 380 mm
Spine Thickness at Base: 2 mm
Blade Height: 59 mm
The Boss Bunka is an oversized take on the bunka profile, stretching to 225mm blade length and 59mm tall - tall enough to function as a tall nakiri, long enough to handle proteins and longer slicing runs, with the sharply defined k-tip that makes the bunka format so useful for precision detail work. The R-2, also known as SG2, powdered stainless steel core is hammer forged in a san mai construction and hardened to approximately 62-63 HRC. That hardness is what allows the kasumi finish grind to run as thin as it does without sacrificing edge stability - the spine is just 2mm at the base, and the blade is ground to a double 50/50 bevel that produces minimal wedging through dense produce. The octagonal rosewood handle keeps the whole package light and balanced for extended prep sessions.
Care Instructions: R2/SG2 powdered stainless is highly stain-resistant but hard and chip-prone at high HRC. Hand wash and dry after use - avoid the dishwasher. Use wood or rubber cutting boards only - avoid bones, frozen foods, and hard materials. Strop regularly between sharpenings and use a consistent angle and light pressure at the stone to maintain the acute edge geometry.
