Akuma After unlocking Sakura, Dan, Cammy, Fei Long, Gen and Rose, Play with someone you've beat the game with and get at least 1 perfect (on single round matches) and use no continues.
Cammy End the arcade mode with Crimson Viper
Dan End the arcade mode with Sakura
Fei Long End the arcade mode with Abel
Gen End the arcade mode with Chun-Li
Gouken Complete the game with Akuma. Then (in single round matches) get at least 1 perfect, 3 Ultra Finishes, 5 first attacks and don't use any continues.