Nezumi was always regarded as a prodigy. Her father in particular pressured her to use her skills to make something of herself. Eventually she left for Empire City so she could use her gifts how she wanted. She got herself a garage she could use as a lab and started attending Empire University

Nezumi was already struggling to get on her feet when Eggman took over the world. She managed to survive and even use it as an opportunity to study Eggman's technology, but she never joined the Resistance or worked up the bravery to stand up to Eggman's forces.

Even after the war was won Nezumi was still feeling defeated. That's when she met Pipsqueak. He managed to bring some light back into her life and she offered him a place to stay in her garage in exchange for bringing her whatever interesting scraps he finds and testing out her inventions for her.