Rumy I guess is the comic relief for the movie, though her destiny is a great one. Throughout she is complaining and eating and being lazy, but when things come to a conclusion, you will find her with Patty and Rabby wanting to stay and fight a good fight.
Rumy's voice actress is Yamamoto Yuriko. Besides starring in Gall Force Eternal Story and the parody anime called 10 Little Gall Force, Ms. Yamamoto played Lamidia McKenzie in the Gall Force Earth Chapters and Iczer-1 in Iczer-1 and Iczer-3. In Gall Force 3:Stardust War Rumy has a brief cameo.