These traditional Kasumi style Japanese Knives are true one-sided knives. This means that the blades are fairly thick, and the back side is concave. This allows you to sharpen the face of the knife, then flip it over and lay the knife flat on a stone to remove the burr. Due to the concave shape, only the spine and edge will touch the stone, so you will not scratch the back of the knife. Deba’s are the work-horse of this series used for filleting fish and general purpose work. Yanagiba’s are for slicing meat and fish, while the Usuba is used for vegetable preparation.