The year is 3199. A powerful enemy from a neighboring galaxy has invaded the Milky Way and beaten the forces of the galactic Alliance, a coalition of many stellar nations, in battle after battle. Fleets are destroyed until only six remain. With the Alliance headquarters gone and the central Alliance close to collapse, the Great Yamato Zero unexpectedly sets out to support the Alliance in one final, decisive battle. Zero is a science fiction OVA built around large-scale space warfare and a civilization's last stand.