Shuji Yamaguchi: Japanese Knife Sharpener & Tokushu Collaborations
Updated August 29, 2026.
Shuji Yamaguchi is a Japanese knife sharpener whose work is documented by Suisin, public event records, specialist product listings, and Tokushu Knife product records. This profile separates those documented facts from claims that cannot be independently verified.
What is documented
- Suisin identifies Yamaguchi as the sharpener and blade artisan on a Shiroichi-ko Honkasumi yanagiba forged by Miwa Ikeda.
- Suisin's Honkasumi Plus record credits Kenji Togashi with forging and Shuji Yamaguchi with sharpening.
- Suisin's 2018 Korin event notice lists Yamaguchi for sharpening demonstrations. An independent Daily Sun event report also names him as the participating sharpener.
- A specialist retail record from Ikyu Japan Avenue credits Yamaguchi with sharpening an Itsuo Doi Blue #2 takohiki.
Why the sharpener's role matters
Sakai City describes traditional knife production as a division of labor that includes forging, sharpening and honing, and handle fitting. After forging, the sharpener corrects the blade's shape and works through rough, intermediate, and fine stones to prepare its geometry and edge. That work is distinct from the blacksmith's role.
Public sources show Yamaguchi sharpening knives from more than one maker. They do not establish a single universal “signature grind” for every knife associated with him. For that reason, Tokushu describes geometry, steel, finish, and care from each individual product record.
Documented Tokushu Knife collaborations
- Nakagawa × Tokushu White #1 Mizu Honyaki Mirror Gyuto 240mm — an active catalog example whose record identifies Shuji Yamaguchi as the sharpener. Availability changes.
- Yoshikazu Tanaka Blue #1 Damascus 210mm Gyuto — a historical Tokushu record identifying Yamaguchi as the sharpener; sold out when this page was reviewed.
- Nakagawa × Tokushu White #2 Mizu Honyaki 255mm Gyuto — a historical Tokushu record identifying Yamaguchi as the sharpener; sold out when this page was reviewed.
We omit attributions when the underlying product record does not identify the sharpener.
Choosing and maintaining one of these knives
Use the individual product page—not a general biography—to confirm the steel, blade construction, dimensions, handedness, handle configuration, and current availability. Care and sharpening requirements vary by knife. For maintenance performed by Tokushu Knife, see our professional hand-sharpening service.
Questions customers ask
Is Shuji Yamaguchi the blacksmith?
Not on the examples cited above. Those sources identify Yamaguchi as the sharpener and name Miwa Ikeda, Kenji Togashi, or Itsuo Doi as the smith or forging artisan for the relevant knives.
Does every Yamaguchi-sharpened knife have the same grind?
No reliable source reviewed for this page establishes one universal grind across every knife. Evaluate the specifications and photographs of the specific knife.
How many knives does he sharpen each year?
We found no reliable public source supporting a fixed annual production number, so Tokushu does not publish one.
Can customers send knives directly to Yamaguchi?
The sources reviewed for this page do not verify a public direct-to-consumer sharpening service. Tokushu Knife's own sharpening service is separate.
Should these knives be treated as investments?
Tokushu makes no promise that a knife will appreciate in value. Choose it as a cutting tool based on its maker, construction, condition, geometry, and suitability for your work.
Sources
- Sakai City — Traditional Cutlery
- Suisin — Miwa Ikeda Shiroichi-ko Honkasumi
- Suisin — Honkasumi Plus
- Suisin — Sharpening Mechanism
- Suisin — 2018 Event at Korin
- Daily Sun — Korin event report
- Ikyu Japan Avenue — Itsuo Doi Blue #2 Takohiki
Written by Anthony Maciejewski, Founder & Director of Tokushu Knife. Source review completed August 29, 2026.