Secret Characters
     These  characters  are unlocked after beating arcade mode for the 
first time:

Free:               Complete arcade mode

Medusa:             Beat Maka's Adventure Mode

Ox and Harvar:      Complete arcade mode



Unlock Excaliber
     After  you  beat  Adventure Mode, Enter Adventure mode again. You 
will get more people to fight. After you beat 49, go to the Cave where 
Excaliber  is.  You  will  see Battle 50 there. Watch him do his dance 
(you  don't have a choice :-D) and Beat Excaliber 5 times in a row and 
he will be available.



Hidden Costumes
     Beat  arcade mode with a character afterward L+O at the selection 
screen.