The Big O(1999)

The Big O is a noir-tinged anime series set in Paradigm City, where residents have no memory of their past. Forty years prior, the entire population's minds were erased, leaving them adrift in a sprawling metropolis controlled by a shadowy corporation. Cut off from the outside world by barren wastelands, the city functions as a police state. Roger Smith, a skilled Negotiator, works to maintain order and keep society functioning, brokering deals and resolving conflicts in this strange, amnesiac world. As Smith navigates his cases, the show gradually peels back layers of mystery surrounding the city's true nature and the conspiracy behind its collective amnesia.