Eiji is an Earth Federation Forces member stationed on Earth in the distant future of the Universal Century timeline. His duties include exploration and investigation of geological formations, leading to his discovery of the "Beauty Memory" object during a mission with teammate Glenn. This artifact is found buried within a high-altitude, massive rock bed on Earth.

Following this discovery, Eiji travels to a 600-kilometer-wide ring structure in lunar orbit. Atop a rock formation within this ring colony, he encounters the mysterious entity Beauty. She identifies herself as the "Beauty Memory" and reveals she contains humanity's collective memories. Beauty directs Eiji to retrieve "Amuro's Legacy" from outside the ring structure, stating that "Amuro's memories" are essential to unlocking her data and achieving mankind's salvation.

In response, Eiji undertakes a critical mission: he steals a Gundam-type mobile suit from the ring colony, which bears a strong resemblance to the historic RX-78-2 Gundam. Accompanied by a young woman named Yuria, whom he escapes with after a large explosion at the ring colony, Eiji pilots the Gundam on a quest to locate "Amuro's Legacy." This quest forms the core of his actions within the narrative.