A normally nice person, Vanilla transforms into Alter Woman when her hero-ness is taken from her. Vanilla is a member of the Science Task Force who patrols the city of Miniature World in a laser-shooting V.F.O. When faced with larger threats, Vanilla transforms into her secret identity of Alter Woman to fight them on equal ground.
After escaping from Killer Hands with the V-Film, Jasmine enters into Vanilla's world and is immediately confronted by the tiny heroine. Though Vanilla tries to act tough, Jasmine takes her V.F.O. (with her in it) and uses it to fight off Madow. Later, the pair are cornered by Queen Heinderella, who strips Vanilla of her hero-ness and turns her to evil. Joe arrives in time to save Jasmine, but Vanilla transforms into Alter Woman and battles him. Once defeated, Vanilla is freed from Madow's control.
In the end of the game, it is revealed that Vanilla willingly chose to join Madow as part of Junko's test for her children.
- Though Vanilla and her world is scaled to her size, she is actually tiny compared to Viewtiful Joe and Jasmine.
- Vanilla's alter-ego, Alter Woman, is a parody of Ultraman, a famous and similiar size-shifting hero in Japan.