The city of Paradigm City is a city of amnesia, though that is said despite the fact that the entire world lost its memories. However, Paradigm City is the last standing of human civilization, as after the events that took place forty years in the past, there isn’t much left to the world outside of Paradigm’s domes. Despite the fact that human beings have adapted and have continued to use complex machinery in order to make their lives easier, many individuals question why they know how to do basic ordinary functions: it is this search for memories that drives nearly everybody to the brink of insanity in Paradigm City.
However, there are those who prefer not knowing any more about themselves than they need to. Roger Smith, Paradigm City’s top negotiator, goes about his affairs in the city of amnesia without worrying about whom he is or where he came from, though there’s something unique about Roger Smith. He is the Dominus of Big O, an ancient MegaDeus that only he can control; though he tends to deny the fact that it was his destiny to control the MegaDeus. With his Big O, Roger sets off in an attempt to defend Paradigm City from those that would seek it harm, though he soon comes to learn much more about himself and the true purpose of Paradigm City.