It's Ciel Phantomhive from Black Butler, from the episode where he is disguised as a girl.
It seemed as thought the basic line of the dress could be re-fashioned from a 1980's prom dress and surely I could find such a dress at the thrift shop. And despite having a theory that you cannot enter the thrift shop looking for a specific garment, and instead must clear your mind, I did find this after a few weeks of diligent searching
It was rather spectacularly 1980's--I think there had to be at least someone in my senior class who wore this. But it had promise. I was able to remove the sequined lace overlay and the ruffle around the neck. I gathered up the front of the skirt on both sides, and hand sewed black ribbon down the front, adding two bows to the bottom.
I pleated white satin for the ruffle around the neck, and created a satin rose from the fabric left over from the ruffle I had removed. The black and white ribbon I found at Joann's, it was a little stiffer than I wanted but worked okay. I added a ruffle to the bottom of the gown--which unfortunately didn't exactly match, but Miranda said it was fine. I think she was starting to grow a little weary as I became fanatical about the details. There is also a dark pink ribbon sewn to the bottom ruffle.
Hanging the dress from a hanger doesn't show the shape very well, but I'm taking this pictures long after she wore it for the convention and I couldn't convince her to put it back on again. The underskirt is a wedding crinoline I also found at the thrift shop and added a satin ruffle to the bottom, as well as rows of eyelet ruffle in the back.
The back has a mock lace-up effect over the zipper
And then the hat. I found a straw hat, again at the thrift, and covered it with pink satin. I handsewed black ribbon around the edge, and hot glued pink roses from the dollar store.
At one point I was tracking the cost of the cosplay--the dress I think was around 5.00, the crinoline was 7.00, and the fabric for the ruffles and hat was maybe 20.00? Ribbon and lace may have been another twenty, the eyelet was from my stash. The ruffles were really most of the work, I'm not sure how much time I saved buying the dress and for a more serious cosplay it probably would have been better to build the entire thing so that there weren't differences in the shades of pink. But I was very pleased how it turned out and although slightly dismayed that it was only for one night, it would have been the same for a prom dress and she had a great time.