Saya Yatomi is a popular idol, possibly as popular as Ultra Rare once were in Cardfight!! Vanguard (as most vanguard players know who she is). Her catchphrase is "With a hop and a step, she conquers the universe!". She tends to add "-myu" at the end of her sentence, possibly to increase her cuteness value and as her own unique identity.
She uses a Bermuda Triangle deck with Miracle Voice, Lauris as her ace. Cardfight!! Vanguard Wiki