During Japan's Nanboku-chō and Muromachi periods, the katana evolved from tachi in regions like Kyoto and Bizen, with curved single-edged blades optimized for samurai duels and warfare. Differential hardening created resilient edges used in Sengoku conflicts.

The katana embodies bushido in Japanese poetry and Noh drama, influencing haiku masters. Its mystique inspired Western poets and novelists, fostering appreciation of Eastern martial aesthetics in modern global literature.