Mutsumi Wakaba is a first-year student at Tsukinomori Girls' Academy. She goes by the stage name Mortis and is the rhythm guitarist of Ave Mujica.

She is a minor character in MyGO, however she does play a vital role in the show, on top of that, during the last episode, her band performs a song, so it will also be expected of Ave Mujica members to sing as well. Here is an example of her speaking. (turn on English subs for video!)