I think the winner in the end will be Team O.
(Before DOA5 release, they did the same thing about bunny suits and Hitomi won, but that's given Kasumi and Ayane were already included in the FREE DLC, so no need to vote for them in DOA5)
This time for DOA5U, all these costumes are called IDOL costumes which are obviously inspired by the popular Japanese IDOL group AKB48. That IDOL group is divided into Team A, Team B, Team...
If you are in Japan or in Asia, you will know that...the wordings are following the same manner like that same Idol group voting which is happening right now. So they are having fun and doing this vote the same way in Team A,K,B...I mean Team D, O, A.
If you are familiar with THAT IDOL group, you will instantly recognize the costume and why...
(The most recognizable one is of course the costumes in Team O, similar, not 100% the same.)
Virtua Fighter 5 actually has the same IDOL costume (those costumes in Team O, similar, not 100% the same.)
Tekken also did use the same wording for some marketing thing as well in Japan.
If you ask why they add an IDOL group costume, that's because it is popular, actually super popular, no actually, extremely hot and super popular that even LF2K and friends buy their CDs and listen to their music almost every day and every month.
And also, Koei-Tecmo actually has developed a mobile phone game for AKB48.
http://www.gamecity.ne.jp/akb48/index.html
Anyway, like Team Ninja said before, they are a Japanese developer and their Japanese core and culture thing will always be there. This is one of it and I think they got it right on! And I think Japanese and Asian players will like this a lot including me. Bunny suits for their target audience, cheerleader uniform for western players, and now idol costumes which suits Japanese & Asian players...You can see this new Team Ninja is improving with better taste.