In-game reset:
Hold Start + Select for three seconds during game play.

Hidden fighters:
Gouki, Morrigan, Nakoruru, Evil Ryu, and Shin Iori cost 300 points. Play versus, arcade, training, or pair match modes to get points. Buy them from the character shop in price mode. Other extra characters cost 50 points. Note: You cannot buy Ryu, Iori, Dan or Joe.