Fight as Ryuju Yamazaki and the Jins
Finish and save your game. Exit, then restart. Now slect the "Load Save Data" option, followed by the "New Game" option. Next highlight these characters in order at the character selection screen and press Low Kick one time on each fighter: Terry, Hon Fu, Mai, Geese, Bob, Sokaku Mochizuki, Andy, France, Joe Higashi, and Blue Mary. A message will appear to verify entry.

Hidden song
Just insert the disc into a standard audio CD player and skip to track 41.

Small fighters
First select Vs mode, then hold the Low Kick and High Punch buttons for both players while your choosing fighters on the character selection screen.