In Kaiba, memories can be stored as computerized information, so that when people's bodies die, their minds can live on. This digitization of mental information allows both the transference of one's mind to someone else's body, and the theft and alteration of other people's memories. Society has fallen apart as authority has become lost and stagnant. In the skies are roiling clouds and electrical storms, impossible to pass without losing one's memories; above them lies the elusive realm of the rich and powerful, who barter others' bodies and memories for their own enjoyment and longevity. Below lies a troubled and dangerous world where good bodies are hard to come by and real money is scarce.