A deba is one of the key traditional Japanese blade styles. In Japan, the deba is a heavier knife and is used primarily for breaking down and filleting fish. Some cooks like it for working on poultry as well. The Kai Wasabi Deba is a medium-sized deba with the traditional single-bevel blade. This gives it an extremely sharp edge that will move through your fish quickly and easily, producing a very clean fillet. The deba is not intended to be used to chop through larger, heavier bones.