Play as Dante:
Beat the game.

Play as Silvia:
Beat the game on Adult.

V-Rated mode:
Beat the game on Adult.

Play as Alastor:
Beat the V-Rated mode.

Ultra V Rated difficulty:
Beat the V-Rated mode.

Play as Captain Blue:
Beat Ultra V-Rated mode.

Thanks to Revolution readers Patzo, Yub-nub and Kaptain Kat!