Historically, katana (刀) were one of the traditionally made Japanese swords (日本刀 nihontō).They were also called うちかたな，Uchikatana.The katana is generally defined as the standard sized, moderately curved (as opposed to the older tachi featuring more curvature).In order to achieve the fastest pulling speed, the katana was worn with the cutting edge up with the saya insert in the belt. By putting the kissaki upside, the edge side is thought as the front of the katana. And the mei is on the left side of blade, so the obverse side of a katana is the left side. According to the modern classification, katana are refer to the swords which blade length (kissaki to munemachi)is between 60-80 cm.