The story is set in the distant future when the world population has begun to shrink after reaching its peak. The "Supernatural Renovation Project" splits Tokyo with towering walls into several Cluster neighborhoods, each with its own unique genetically modified populations, governed by artificial intelligence.
Most people live their lives in their own unique Clusters, blissfully unconcerned with life beyond. However, there are some who seek to escape to the other Clusters. An outfit helps those who wish to escape. (source: ANN)