Set in the mid-21st century, Tokyo has been transformed into a tropical metropolis due to the effects of global warming. In an effort to decrease temperatures in the city's center by 5°C (9°F), officials have initiated a massive project to convert the city into the world's largest forested city, named Atlas. While many are seeking refuge in Atlas, few are able to call it home. Adding to this challenge are anti-government guerilla efforts aimed at impeding the city's forestation.