Asteka
To unlock Asteka, you must defeat him in Scout mode. But first, you must have already defeated Spice.
B.T.
To unlock B.T. for arcade mode, defeat him in scout mode.
Gio
To unlock Gio, you must defeat him in Scout Mode. But first, you must have already beaten Silver Man.
Kojiromaru
To unlock Kojiromaru, you must defeat him in Scout mode. But first, you must have already beaten Gio.
Misha
To unlock Misha, you must defeat her in scout mode. But first, you must have already beaten Prince.
Prince
To unlock Prince, you must defeat him in Scout mode. But first, you must have already obtained Puma.
Puma
To unlock Puma, you must defeat him in Scout mode. But first, you must have already unlocked B.T.
Silver Man
To unlock Silver Man, you must defeat him in Scout mode. But first, you must have already defeated Misha.
Spice
To unlock Spice, you must defeat her in Scout mode. But first, you must have already beaten Kojiromaru.