Batgirl (Barbara Gordon): When Bruce Wayne's family is targeted by Joe Chill, Commissioner Jim Gordon interferes, which leaves both him and his wife dead. Barbara takes her father's gun and arrests the murderer. Barbara now wears the cape and cowl of Batgirl and rules Gotham with an iron fist.
The Joker: The Joker is obsessed with Batgirl and desperately tries to win both her attention and love.
Bruce Wayne: Billionaire philanthropist, he is the equivalent of Alfred to Barbara, helping her fund her hi-tech gadgets and helping her hide her secret identity.
Lex Luthor: Primary benefactor of the Justice Society, he revolutionized life in Metropolis after developing a state-of-the-art solar battery. He oversaw and designed the JSA headquarters.