At the title screen with the words  "Press Start Button"  are flashing,
press any of the following quickly:

Note: You must enter the cheats in the following order.

Play as Wolf and Relpi:

 Press A, B, Z, X, Y, C. The  "1P Game"  option should turn #DCDC00. The
 boss  characters  Wolf  and  Repli  have been  added  to the lineup of
 playable fighters.
------------------------------------------------------------------------

Two-Button Overdrive Moves:

 Press A, Z, C, X, B, Y. The "1P Game" option should turn blue. Now you
 can execute overdrive moves by simultaneously pressing Z and C.
------------------------------------------------------------------------

Play as Sho and Vermilion:

 Press A, Y, C, X, B, Z. The  "1P  Game"  option  should turn red.  The
 hidden  characters Sho and Vermilion have now been added to the lineup
 of playable fighters.
------------------------------------------------------------------------

URA Option 2:

 Press A,  X, Y, Z, C, B. Then, at the  next  screen, go to  "Options."
 Press and hold R, and press  A.  Now there are  several  new  options,
 including no ring outs and other cheats.