Katana, whose real name is Tatsu Yamashiro, is a superheroine in DC Comics, first appearing in The Brave and the Bold #200 (July 1983), created by writer Mike W. Barr and artist Jim Aparo. A highly skilled Japanese samurai warrior, Tatsu led a peaceful life with her husband Maseo Yamashiro and their two children until tragedy struck. Her brother-in-law, Takeo Yamashiro, driven by jealousy and affiliation with the Yakuza, set fire to their home, killing the children, and subsequently slew Maseo with the mystical Soultaker sword. Tatsu claimed the blade after defeating Takeo, adopting the identity of Katana to pursue justice and vengeance against those who prey upon the innocent.

The Soultaker sword serves as Katana's signature weapon, a supernatural artifact that traps the souls of those it kills, enabling her to communicate with the captured spirits, including that of her deceased husband Maseo. This connection provides tactical advantages in battle but also imposes a profound emotional burden. Trained rigorously in traditional martial arts and swordsmanship, Katana is an expert combatant, proficient in various forms of hand-to-hand fighting and wielding the blade with lethal precision. Her abilities, combined with her unyielding resolve forged from personal loss, establish her as one of the most formidable melee fighters in the DC Universe.

Throughout her publication history, Katana has been prominently associated with the Outsiders, a team personally assembled by Batman for covert operations beyond the Justice League's scope, where she served as a founding member. She later joined groups such as the Suicide Squad, Birds of Prey, and Justice League of America, contributing to high-stakes missions. Significant developments include her exploration of the sword's potential corrupting influence in solo stories during the New 52 era and recurring roles in team dynamics that highlight her disciplined yet haunted persona, cementing her status as a resilient anti-heroine.