By Anthony Maciejewski • Updated August 2, 2025
Who Is Shuji Yamaguchi?
Shuji Yamaguchi (山口修二) is Japan’s pre-eminent togishi—a specialist who grinds, polishes, and finishes blades forged by Sakai’s greatest blacksmiths. Over three decades, he has perfected the hamaguri (convex) grind, a geometry that marries laser-like thinness with durability. His mirror-polished bevels not only look stunning; they reduce drag and give each knife that coveted “melting through food” sensation.
The Signature Convex Grind Explained
Unlike a flat V-grind, Yamaguchi-san’s convex profile tapers smoothly from spine to edge. That curvature pushes food away from the blade road, preventing sticking, and supports an ultra-keen apex that lasts. Every bevel is set by hand on a progression of large water-stones and natural finishers—no machine can replicate his instinct for steel.
Exclusive Tokushu Knife Collaborations
We’ve partnered with Shuji Yamaguchi to create a trio of collector-level knives, each forged by a living legend and finished to perfection in his Sakai workshop.
1. Yoshikazu Tanaka × Yamaguchi — Blue #1 Damascus Gyuto 210 mm
Tanaka-san’s ethereal Blue #1 Damascus billets meet Yamaguchi’s full convex grind in this limited-edition 210 mm gyuto. Expect glass-smooth push cuts and a mesmerizing ripple pattern under the mirror finish.
2. Yoshikazu Tanaka × Yamaguchi — Blue #1 Mirror-Finish Bunka
For those who favor mid-blade versatility, the Blue #1 Bunka 180 mm showcases Yamaguchi’s unrivaled mirror polish. The hamaguri bevel glides through product while the flat tip excels at fine veg work.
3. Satoshi Nakagawa × Yamaguchi — White #2 Mizu Honyaki Gyuto 255 mm
Water-quenched honyaki is the ultimate sharpener’s test. In this 255 mm gyuto, Yamaguchi brings out the hamon under a smoky-glass polish—an heirloom piece designed to sing on the board.
Why Invest in a Shuji Yamaguchi Knife?
- Peak performance: Razor keenness plus convex food release equals faster, cleaner prep.
- Collectability: Each piece bears the fingerprints of two masters—its smith and its sharpener.
- Future value: Limited runs mean scarcity; Yamaguchi-finished knives often appreciate among enthusiasts.
Care & Sharpening Tips
Maintain Yamaguchi-ground edges by staying on his convex bevel. Use a medium whetstone (around #1000 grit) with light pressure; raise the spine until you feel the native curvature engage, then follow through the length of the blade. Finish on a fine stone or uchi-mono natural finisher for that tell-tale haze and bite.
Frequently Asked Questions
Is Shuji Yamaguchi a blacksmith?
No—he is a master togishi, specializing exclusively in grinding, polishing, and finishing blades forged by others.
How many knives does he finish each year?
Estimates place his output under 2,000 knives annually. Given global demand, each release sells out quickly.
Can I mail him my knife to sharpen?
Yamaguchi-san works directly with manufacturers and retailers; he does not offer a private sharpening service.