Street Fighter II: The World Warrior, released in 1991, was the first true sequel to the original Street Fighter. It was one of the earliest arcade games for Capcom's CPS hardware and was designed by the duo of Akira Nishitani (Nin-Nin) and Akiman (Akira Yasuda), who were previously responsible for Final Fight and Forgotten Worlds. Notably, even when Street Fighter II was released, Capcom had no idea what sort of phenomenon it was about to create. It believed that the game would do somewhat (but an unknown quantity) better than its CPS-based contemporary games, Final Fight and Mercs.