Mumi-chan is Chichi-chan's imouto who begs for him. She is a squirrely girl whose pouty face has the power to melt any person's heart. She never leaves home without her stuffed bear named Usagi-chan that she has had since infancy. She is not yet potty trained despite being four years old and will often ask Chichi-chan to help change her. . Mumi-chan (not, just feels) kawaii!!, bakes cookies, don't ask where she comes from