I wasn't sure what this was parodying when I first saw it, but having looked at the design recently (unfamiliar with the series itself), I think it is Kujou Hikari of Futari wa Pretty Cure (official site character link: http://www.toei-anim.co.jp/tv/precure_MH/ch_hikari.html ). The costume looks very similar with a few differences like crosses instead of hearts. Both characters are voiced by Tanaka Rie, so also likely a seiyuu joke too. I'll go ahead and tag it as such.