Press Left, Right, Left, Right(2), Left, Right, Left at the "How To Play" screen.
Fight as Ryuji Yamazaki and the Jin twins
Enter the character selection screen. Highlight the following characters (in order) and press X before moving on to the next person. A sound will be heard each time X is pressed: Terry, Hon Fu, Mai, Geese, Bob, Sokaku Mochizuki, Andy, France, Joe Higashi, and Blue Mary. The portrait for Ryuji and the Jin twins will appear on the character selection screen to confirm correct code entry.