During their fifth-anniversary special web program “THE MIATCH” streamed on YouTube last night, the three-member anison vocal unit Mia REGINA announced that they will perform the OP theme song “Fever Dreamer” for the forthcoming fall 2021 TV anime Gyakuten Sekai no Denchi Shoujo / Rumble Garanndoll.
Mia REGINA, managed by DEARSTAGE (Dempagumi.inc, Moso Calibration), was formed by Waka Kirishima, Fuuri Uebana, and Risuko Sasakama in August 2016.
All of the three were original members of STAR☆ANIS, the song performer unit for the Aikatsu! franchise.