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: SG2 is a stainless powdered steel, but the high hardness means it can chip if it meets something it should not. Use wood or rubber cutting boards only, avoid bones, frozen foods, and hard rinds, and hand wash and dry the blade rather than putting it in a dishwasher. Strop regularly between sharpenings to maintain the edge geometry. We do not currently carry a wooden saya that fits this knife.
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: SG2 is a stainless powdered steel, but the high hardness means it can chip if it meets something it should not. Use wood or rubber cutting boards only, avoid bones, frozen foods, and hard rinds, and hand wash and dry the blade rather than putting it in a dishwasher. Strop regularly between sharpenings to maintain the edge geometry. We do not currently carry a wooden saya that fits this knife.
- Maker: Takayuki Shibata
- Location: Fukuyama, Japan
- Type: Boss Bunka (Tall and Long)
- Construction: San Mai, Hammer Forged
- Edge Steel: SG2 (R2) Powdered Stainless
- Cladding: Stainless
- Blade Finish: Kasumi
- Hardness: ~62-63 HRC
- Bevel: Double, 50/50
- Handle: Octagonal Rosewood
- Weight: 6.2 oz (178 g)
- Blade Length: 225 mm
- Total Length: 380 mm
- Spine Thickness at Base: 2 mm
- Blade Height: 59 mm
