Government & History
Neo Japan's government structure is that of a democracy with an elected prime minister, similar to modern-day Japan. During the G Gundam series, Ulube Ishikawa was one of the high officers of Neo Japan's military and there was Commissioner Karato who was the main decision maker during the Gundam Fight.
Since the Gundam fight was a replacement for war to see who would have control of the Universe, Ulube and Dr. Mikamura schemed against the Kasshu family in order to gain control of Dr. Raizo Kasshu's new developmental Gundam for military purposes. Ulube's plan later would bring the Devil Gundam to the Neo Japan colony and resurrect it with the help of Dr. Mikamura's daughter, Rain Mikamura, to its final form, causing a Universe wide war to stop it from consuming Earth and killing all of mankind. In doing so however, the Devil Gundam fused with the entiry colony of Neo Japan itself, turning it into a continent-sized fortress adorned with a Gundam body at its core. Domon Kasshu, Dr. Kasshu's son, and the rest of the Shuffle Alliance were eventually able to destroy the Devil Gundam for good and Ulube was killed along with it. The resulting destruction of the Devil Gundam left the colony in ruins, with an enormous skeletal structure of the Mobile Fighter to serve as a reminder of Ulube's deceit.
It is said that Master Asia was once the Gundam Fighter for Neo Japan during the 7th Gundam Fight. However, it is unknown if this is actually official or not.
Ulube Ishikawa was the fighter of Neo Japan during the 12th Gundam fight. Piloting GF12-xxxNJ Ulube's Gundam, he makes it to the Gundam Fight Finals, only to lose to Master Asia, this loss shaping the things to come.
Domon Kasshu is the Neo Japan Gundam fighter during the 13th Gundam fight in Mobile Fighter G Gundam. He first pilots the GF13-017NJ Shining Gundam but when that one is destroyed on the Guyana Highlands while fighting the Devil Gundam it is replaced with the GF13-017NJII God Gundam. Neo Japan becomes the winner of the 13th Gundam Fight, earning the right to govern all of Earth.