The basic Traditional Japanese Knife shapes are YANAGIBA (Long slicing knives) DEBA (Heavy Knife used for fileting a beheading fish) and USUBA (Cleaver shape for vegetables). They are true one sided knives with the edge coming to a chisel point. The front side has a pronounced bevel known as the shinogi line. The back side is concave so that when laid on a sharpening stone, the only part that touches is the cutting edge, spine and a bit of the tip. This allows you to sharpen the back side of the knife without scratching it up. Many chefs simply lay the front of the knife on the stone with the shinogi line flat and sharpen. Then lay the back of the knife flat on the stone simply to remove the burr.
Please note that these are pure carbon steel knives and will rust if not wiped dry after each use.