Designed by (土井勝) Doi Katsu (the Osaka TV chef/cooking-school founder) and forged by Masamori. A 210 mm single-bevel slicer (yo-handle sashimi/yanagi profile). A training-friendly blade with graduated tick marks along the face—classic of cooking-school knives meant to teach consistent slice thickness. Laminated build with a carbon-steel core (typical White #2 for this era) clad in soft iron gives that crisp, sticky edge and easy stone feedback. Western riveted handle keeps it stable for long pull cuts. A nimble, story-rich slicer with real lineage to the Doi school.