A kind of polishing material. It is a rectangular, spindle- or crescent-shaped flat stone tool with a blade on one long side. There are blades sharpened on both sides and attached on one side. In the middle of the body there were one or two holes through which the fingers were passed through the wire and used to receive ears of grain. It is a harvesting tool that preceded the scalpel for root cutting in the early agricultural culture of East Asia. Chinese supine culture Stone knives are typically rectangular and have a hole. Yongsan Culture Later, the half moon model was added. In Japanese Yayoi culture, a half-moon pattern with a straight back and a curved blade in the first half of the year, and a pattern with a curved back and a straight or curved blade represent the middle period of Kinki and other regions. This. The name of Ishikencho is the same as the name used in the Meiji period when mixed with a cooking knife, compared to the Women's Knife of the Eskimo. In China it is called a stone sword, but in Japan there is a stone tool with the same name in the Jomon culture, so it cannot be adopted. In cultures with stone fences, other materials may be used instead of stone fences. Some supine cultures use clods of earth and the Yongsan culture uses shells. Kaikenken was excavated in the Ruins of Bishamon Cave in Kanagawa Prefecture in Japan. In addition, there are sharp wood products in the ruins of the Kitagawa River in Osaka Prefecture. The andesite stone blades distributed in the Seto Inland Sea region were cut into holes on both short sides to replace the holes, but they are used for the same purpose. Iron products mined from the ruins of Kashihara in Korea should be considered as improved products, not substitutes, but the shapes are made according to stone fences.