Rumi is Mima's manager. She is opposed to Mima's crossover into acting. She was a former idol singer.

It turns out she is the "real" Mima who was running website "Mima's room" and sending the emails to Me-Mania. She then thinks of herself as pop-idol Mima. Using Me-mania's hands she exacted revenge on all who "spoiled" Mima's pure image in order for her to become actress.