Uraoshi refers to the flat rim on the back sides of traditional Japanese knives (Single edged Knife). The uraoshi surrounds the Urasuki, the integral concave shape on the back sides of traditional Japanese knives. The purpose of the urasuki is to minimize food sticking to the blade (reducing the drag while slicing), hence it has the same effect as perforated and hollow-ground blades. It is essential for the rim of the urasuki to be perfectly flat and level for it to have its full effect. Furthermore, it is essential because it enhances the strength of the blade on the edge of the knife as well as aligning the unbalanced parts on the back side of the blade. Without the uraoshi, the knife cannot be sharpened to reach its full potential and will be brittle.