Kill La Kill is one of those animes that has tons of nudity and revealing outfits without it feeling like fanservice a lot of the time. Also one of those animes that is extremely strange while being incredibly unique and well thought out.
Her father did say it was her wedding dress. Now, being that there are only two kamui in the show, and the traditional color of the groom's tux is black, who is the most likely candidate? Amazing work. I dig the flower motif.