In A.G. 101 (the 101st year of the Advanced Generation calendar) a mysterious entity known only as "UE", or "unknown enemy", attacks and destroys the space colony Angel. This brutal attack becomes infamous as the "The Day the Angel Fell", and marks the beginning of humanity's war for survival. The series begins in A.G. 108 when the UE attack the space colony Ovan, where Flit Asuno now lives after he escaped colony Angel before its destruction. Flit's mother shortly before she is killed by the UE, she gives her son an object called "AGE Device". Within it he discovers the blueprints for a powerful weapon from the past—the ancient messiah named "Gundam."