*Mad Love introduces Harley Quinn as a former psychologist who fell in love with the Joker during her internship at Gotham City's Arkham Asylum and details her transformation into the Joker's villainous accomplice Harley Quinn, as well as the Joker's lack of respect for Harley.

She is also known as Harleen Quinzel, is a DC Comics character who first appeared in Batman: The Animated Series in 1992 and in The Batman Adventures in 1993. Her origin story is that she was a psychologist at Arkham Asylum who fell in love with and was manipulated by her patient, the Joker, eventually becoming his accomplice and lover. Harley Quinn's alias is a reference to the 16th-century Italian theater character Harlequin.*