The long, single-bevel knife used for slicing sushi fish is called a yanagiba. Its name means “willow blade,” describing the knife’s long, slender shape.
Yanagiba is a Japanese sashimi knife designed to produce smooth, clean slices of raw fish for sashimi and nigirizushi. Its long blade lets a chef cut through a piece of fish in one pulling motion, rather than sawing back and forth. This helps preserve the fish’s texture and leaves a glossy, even cut surface.
The knife is typically single-beveled: the cutting edge is sharpened on one side, while the opposite side is slightly concave. This design allows precise slicing and helps the cut piece separate from the blade. Right-handed and left-handed versions are made with the bevel on opposite sides.
The other options are different Japanese knives. A deba is a sturdy fish-processing knife, while nakiri and usuba are primarily vegetable knives. A yanagiba is therefore the canonical answer for slicing sushi fish.