Young Brunette Girl With A Japanese Katana Sword Reveals In The Traditional Washitsu Room With Tatami Flooring

With a few exceptions katana and tachi can be distinguished from each other if signed, by the location of the signature (mei) on the tang (nakago). In general the mei should be carved into the side of the nakago that would face outward when the sword was worn. Since a tachi was worn cutting edge down and the katana was worn cutting edge up, the mei would be in opposite locations on the nakago of both types of swords.
The katana is characterized by its distinctive appearance: a curved, slender, single edged blade, 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 cutting ability.