Super Street Fighter II Turbo, released in Japan as Super Street Fighter II X: Grand Master Challenge, is a competitive fighting game released for the arcades by Capcom in 1994. It is the fifth arcade installment in the Street Fighter II sub-series of Street Fighter games, following Super Street Fighter II. Like its predecessor, it ran on the CP System II hardware. Super Turbo introduced several new play mechanics to the game system from the previous Street Fighter II installments, including the addition of powered-up Special Moves called Super Combos. It also introduced the hidden character of Akuma, who would go on to become a recurring character in later Street Fighter installments and other Capcom fighting games.