Domon is chosen as the representative of Neo Japan in the 13th Gundam War. He takes on this role with the goal of finding his older brother Kyoji Kasshu and freeing his father from a state of suspended animation. He received training under Master Asia, who won the previous Gundam tournament. Initially, Domon piloted the Shining Gundam but it sustained significant damage. As a result, Neo Japan sent him the God Gundam (known as Burning Gundam in English) to continue fighting in the Gundam War. After training with Master Asia, he was given the title "King of Hearts," which is used by the Shuffle Alliance. Currently, Domon aims to locate Kyoji and the enigmatic Devil (Dark) Gundam, rectify any wrongdoings, and emerge victorious in the Gundam War for Neo Japan's sake.