You know what's weird about this "Special Unit"? Shimizu Saki , Yajima Maimi and Maeda Yuuka are not listed as part of the play NOWHERE on the official announcements, not on H!P Official site, not on Takarazuka's site, not on the official flyer....weird.
but that's the BEAUTY of this single ^_^
I don't see it as BEAUTY because, if it is real, it just means that Eri, Sayu, Koha, Aika, Junjun and Linlin are once again shafted, because if they have a special unit about the musical, I can assume that they would use the people that play important characters on the show for it. As I said, what I find weird is that if these girls would play a significant role on the play, they would be listed at least as part of the cast.
And singing the theme for an anime is not equal to sing a single from a musical. L'Arc~en~Ciel sang the theme from Full Metal Alchemist, and theyy were not doing anything in the show, just an example.