Deba

The Deba knife has a thicker and heavier blade than other knives in order to prevent the blade from losing its edge when cutting the hard bones and heads of fish. In addition, because the single-edged blade cuts on only one side of the blade, the blade does not stick to sticky fish and meat, which has the advantage of locking in the umami without destroying the cells of the food.
In addition to fish, a de-eba knife can also be used for cutting other hard foods. For example, when cutting hard vegetables such as squash, a single-edged knife with a thicker and sharper blade is more useful than a double-edged knife of the all-purpose type.