Megumi Ooumi is a 14 year old pop star, and The Keeper Of The Book to a 6 year old mamodo Tio. She is often seen in video games or doing concerts but despite all this remains a normal girl.
Megumi first met Tio when she found her injured on the docks. At first, Tio had kept harshly to herself when they'd first met, saying that Megumi would only get hurt helping her fight off mamodo. They eventually started to get along and Tia came to trust Megumi.