Expert Mode
To get the expert mode, press [Back], [Forward], [Back], [Forward], then [Forward], [Back], [Forward], [Back] at the how to play screen.
Unlock Yamazaki and the Jin twins
To unlock Ryuji Yamazaki and the Jin twins do the following (Taken from the manual):
During the character selection screen, highlight the following characters in the order listed below and press the [X] button ([LK] button) once on each character. You will hear a chime each time.
Terry, Hon Fu, Mai, Geese, Bob, Sokaku Mochizuki, Andy, France, Joe Higashi, Blue Mary.
When done correctly Ryuji and the Jin twins will apprear on the selection screen.