The King of Fighters fighting game series, produced by SNK, includes a wide cast of characters, some of which are taken from other SNK games. The story takes place in a fictional universe in which an annual series of 3-on-3 or 4-on-4 fighting tournaments are held.
The first game in the series introduces the initial main character of the series, Kyo Kusanagi, a young Japanese fighter who is the heir to a powerful group of martial artists having pyrokinetic abilities. Kyo fights against the Kusanagi clan's enemies, his rival Iori Yagami, and the snake demon Orochi and its human followers, among others. The first four games in the series revolve about these fights, while The King of Fighters '99 introduces a new story arc, revolving around K′, a young man who seeks to destroy the mysterious NESTS organization because they kidnapped him at an early age and stripped him of his past memories, so that they could force him to be a fighter under their control. In The King of Fighters 2003, a new character named Ash Crimson enters the tournament, to steal the powers of the clans who sealed the Orochi in the past for unknown reasons. A new group of antagonists, known as Those From the Past, also appears in the series; they want to obtain Orochi's power for the purpose of giving it to their unknown master. The latest story arc involves the young Shun'ei who possesses unknown supernatural powers connected with Ash's timetravelling paradox and is capable gathering new deities from other dimensions. The cast of the Orochi arc was further expanded EX Neo Blood spin-offs while Maximum Impact deals with new defenders from South Town led by the Miera brothers.
The plot and the characters came from the Yamata no Orochi legend. There are also several characters in the games that are parodies or homages. Merchandise based on the characters has also been released, including action figures and keychains. The characters have garnered praise from several video game publications for the quality of their designs and movesets. Comments focused on the lack of improvements in some of the characters, but added that the roster is greatly diverse.