In the year 4056, humans had settled all four terrestrial planets in the solar system. This gave rise to the four major powers of the solar system: the Earth-Moon Republic, the Venus Empire, Metallic Mercury, and the Mars Federation. The divisions and differences that once separated nations had now spread across the entire solar system. Three social classes, the commoners, the wise, and the mages, together with the mysterious class above them known as the Children of God, made up the solar system's population of around 20 billion. The struggles and rivalries between nations and individuals were once again unfolding, as if history were repeating itself.
