Description : A katana is a Japanese sword characterized by a curved, single-edged blade with a circular or squared guard and long grip to accommodate two hands. It was used by samurai in feudal Japan and worn with the edge facing upward. There are more than 100 Japanese swords designated as National Treasures at the Tokyo National Museum, of which the Kotō of the Kamakura period account for 80% and the tachi account for 70%. Japan.