, is a video game character from The King of Fighters fighting game series developed by SNK. He debuted as the leader of the Hero Team in The King of Fighters '99, released in 1999. He stars as the reluctant hero in the NESTS syndicate story arc of the series. He was created to be a "dark hero" in contrast to the series' previous protagonist Kyo Kusanagi.
K′ is a young man who lost all his memories when the NESTS syndicate captured him and injected the DNA of the powerful fighter Kyo into him to copy Kusanagi's pyrokinetic abilities. Angered by what NESTS did to him, K' betrays NESTS and decides to destroy them for using his body and deleting all his memories. Although he hates tournaments, K' uses the King of Fighters tournaments to find NESTS members and defeat them. In his search, he meets allies who have the same goal and joins forces with them. Aside from the main series, K' also appears in several other media series, such as spin-offs and crossover video games, as well as printed adaptations of the series.
Since his introduction in the series, K' has received both praise and criticism by video game publications. The character's gameplay has been praised for its style and differences from previous known fighting styles. His absence in The King of Fighters XII was controversial and his return in the following game was due mainly to his popularity as a character.