The daughter of an abusive, alcoholic father and a negligent mother, she was abused both at home and at school. The only person that was ever kind to her was her grandmother, who doted upon her. However, Kimura's mind by this point consisted of nothing but emotional scar tissue and was not changed. Eventually, she found her way to the Facility, where they enhanced her genetic code to give her impenetrable skin and enhanced strength. With her new powers, she tracked down anyone who had abused her in the past killed them. She was given the job of being
X-23's handler.