Angelica Burns operates as a private investigator for the Federation Bureau, acutely aware of the government's corruption driven by the Criminal Guild. Her central mission is hunting the criminal Mister, a pursuit spanning at least four years that originated during her earlier career as a traffic cop. While initially driven by professional duty, a significant development reveals underlying romantic feelings fueling her determination to capture him personally. Despite this motivation, she consistently prioritizes his survival against greater threats, particularly from Madame Marciano's 12 Sisters, while maintaining her stated goal of apprehending him herself.

Her personality includes a trait of extreme appetite; she is a notorious glutton, potentially due to a superhuman metabolic rate or hypoglycemia. During her investigation, she gains a partner: Chelsea Moore. Chelsea, initially a young police detective assigned to escort Angelica, resigned upon uncovering police corruption and became her investigative partner.

Mister assigns her the nicknames "Angel" and "Sexy." Her birthday is noted as April 14th.