After her owner gives up on mending her stuffed rabbit, Mi-chan (to which the Character is named after), Yuka's egg is tainted with an X. Amu Hinamori, Rikka Hiiragi, and Tadase Hotori eventually find the X-Egg and Amu purifies it after she reasons with Yuka.
Mi has cream-blond hair put in two ponytails with a curl on each end and bangs with a similar curl. She wears a pink-purple jumpsuit over her body with two white buttons sewn on the jumpsuit. On her hair is a similar white button hair pin.
Mi is a gentle, maternal girl, doing things at her own pace and reassuring others who have given up on the things they wanted to do.