http://gematsu.com/2015/08/dead-alive-xtreme-3-ps4-ps-vita-theme-character-election-started
Free Step Dodge
ESArion
petopia
Sexy Beach all day every day.
panicitstylor
It's just whoever's themes gets downloaded the most will be in the game. Kasumi and Ayane will clearly be there! Don't worry! 
SoftCabbage
This is the result of "digital era" meets PR's "we love you, we listen to you" bullshit, topped with a grain of consumerism.
Brute
No, they actually don't want you, a Westerner, to play DOAX3 at all.