Era background: In 3025, the earth's resources have been exhausted. The solar system is on the verge of collapse due to the exhaustion of solar energy. Because the gravitational system of the solar system has collapsed, the sun continues to collapse, moving away from the center of the solar system. The moon and the earth are getting closer, and human interstellar immigration has made no progress at all. In order to continue human civilization, scientists have invented technology that uses the earth's magnetic field to convert it into energy. It can provide light energy similar to sunlight and continue to barely maintain the continuation of human civilization. This huge device is called the "solar wheel".
The continuous human gathering areas on the earth mainly include 4 large cities and more than ten small human gathering areas. Large cities include Rift City, Airport City, Ark City, and Deep Dive City.
