how about a muscly gal with a toned body who doesn't cover up as you remove clothes
or a more western themed girl that wears a cowgirl hat and has braided hair and freckles
or one of the teachers/school nurse trying to show she can still be spontanious at her age
or the principal herself enters the contest on a bet to shut it down if her team wins
or alternitively you could add male characters(though that may mess up the narrative)
or maybe dip into the fantasy/sifi side of things and add a succubus, elf, or robot character/cosplayer
or maybe add an influencer girl who's only in it for the likes/subs she'll get on her social accounts
also maybe add snippy dialogue between characters during the matches. actually give them some character outside of thier bio. or a story mode could be fun too.