Momono, a mysterious girl who first shows up in episode 8. The fact that she looks like Hotaru is of no consequence because I simply used a picture of Hotaru to modify into the character. She's not really supposed to look that much like Hotaru, if you get what I mean.
Momono models the official colors of the Mirai Mugen uniform here. I finally settled on something!
Art was originally a picture of Hotaru from one of the S anime books. Modified and colored by Laurel.