Without any credits inserted at the title screen, enter: "1P side [A], 2P side [Up], 1P side [B], 2P side [Right], 1P side [C], 2P side [Down], 1P side [D], 2P side [Left], 1P side and 2P side [START] at the same time. If the code was successful, you'll hear the same sound effect as when you select your character and arcana.