Surface is a world above Lux. The people of the surface world seemed to have simply faded away out of apathy, rather than being destroyed by some cataclysm. The surface world is lush but almost completely empty of life. That world has many radios which do nothing but repeat the same phrases over and over again.
It is vaguely presented, but the implications are that the surface-dwellers of the world at least partially predicted the decline of the human species, and isolated those with greatest genetic chances of prospering, which just happen also to be those that create violent tendencies. Also isolated were predecessors of the members of the Class, who were given special privileges in Lux in return for their cooperation.
Interestingly enough, the surface world seems to be stylistically stuck in the past, with old fashioned radios and other outdated technology just laying around, but mixed with various examples of extremely sophisticated tech. It can be said that the surface world is shown to be both highly advanced (see Yoshii and Sakimura's office) and has apparently regressed back into the 1920s.
Trivia[]
- A scenes from the surface world mimic the paintings of Edward Hopper. Of Hopper’s paintings is said in his wikipedia article “His primary emotional themes are solitude, loneliness, regret, boredom, and resignation”. That is the state of the people up above.