The turbulent era known as the Universal Century has ended. Now, mankind looks towards prosperity and peace in the new era known as the Regild Century (R.C.). One of the most important resources in this era is the Capital Tower - a space elevator which towers over the land connecting Earth to space. Its purpose, to transport the Photon Batteries the Earth relies on for power. It is worshipped as a holy place.
Tasked with protecting the tower, one day on a practice mission, young Capital Guard cadet, Bellri Zenam is attacked by a high-performance G-Self mobile unit. Despite having never before encountered the G-Self unit, he feels a strange connection to it and its pilot, a space pirate called Aida Rayhunton.
Little does Bellri know that he is about to uncover truths which will shake the entire Regild Century.