Historically, katana (刀?) were one of the traditionally made Japanese swords (日本刀 nihonto?) that were worn by the samurai class of feudal Japan, also commonly referred to as a "samurai sword". Modern versions of the katana are sometimes made using non-traditional materials and methods. The katana is characterized by its distinctive appearance: a curved, slender, single-edged blade with a circular or squared guard and long grip to accommodate two hands. It has historically been associated with the samurai of feudal Japan, and has become renowned for its sharpness and strength.