In the Future Century (FC), due to the serious pollution of the earth, humans moved to the space colonies and established colonies such as New China, New Japan, and New America. Although each country still has territories on the earth, they have been seriously neglected. In order to avoid war, the countries decided to use a Gundam Fight to determine the ruling power of each colony over the earth. The competition is held every four years, with the earth as the arena. Each country (colony) sends a representative to participate in the competition, and they fight one-on-one with Gundam until there is only one winner. The country to which the winner belongs can obtain the management rights of each colony and the earth for four years, until another country wins the next Gundam Showdown. The residents living on the earth have to endure the destruction caused by the representatives of each country during the battle. The story takes place at the beginning of the 60th year of the Future Century, when the 13th Gundam Fight was about to begin. The protagonist of the story, CodeError! from New Japan, decides to participate in this Gundam showdown in order to track down his brother who stole CodeError! (Devil Gundam) designed based on the three major theories of DG cells: self-proliferation, self-regeneration, and self-evolution. The story begins from here.