Nikko was highly skilled in computers and was already studying calculus at her young age.
She lived with her parents, David Halloran and Keiko Halloran until OCP evicted them to make way for the development of Delta City. During this eviction orchestrated by the Urban Rehabilitators, she became separated from her parents and was taken under the wing of resistance fighters.
She quickly gained the respect of this group during their raid on the police armory Ordnance Depot 7 by hacking into an ED-209 unit and making it as "loyal as a puppy." She used the ED-209 to allow the rebels to break into the facility and escape OCP Security Concepts officers.
Later on, she patched through a CCTV camera feed so that Dr. Marie Lazarus could make an impassioned plea to the people of Detroit, encouraging them to resist OCP.