The Big O was animated by Cowboy Bebop’s Sunrise, previously subcontracted to work on Batman: The Animated Series, which accounts for the show’s influence on The Big O’s singular look.
The Batman vibe is obvious (Roger Smith even has a butler), but The Big O also pulls from other noir private eye stories of Philip Marlowe and Sam Spade.
The Big O is the story of Roger Smith, the Negotiator of Paradigm City, a seemingly post-apocalyptic domed city barely holding it together after a mysterious event 40 years prior in which everyone lost their memories.