In the Universal Century year 0079, the space colony known as Side 3 proclaims independence as the Principality of Zeon and declares war on the Earth Federation. One year later, they are locked in a fierce battle for the Thunderbolt Sector, an area of space scarred by the wreckage of destroyed colonies.

Abandoning their allegiance to Zeon, Daryl Lorenz and Dr. Karla Mitchum join Federation defector Claudia Peer and head for the Nanyang Alliance's Taal volcano base to dedicate themselves to the cause of Sojo Levan Fu. Once there, they learn the full extent of the Nanyang operation to mass-produce the Psycho Zaku and the Reuse P. Device, and Sojo Levan Fu's ultimate plan to end humanity's fall toward inevitable destruction! Daryl and Karla are the keys to this plan, but unlocking their shattered memories has unexpected dangers.