In the future, humanity has moved out of the solar system and started to colonize planets far away from Earth. One of the farthest colonies in existence is the planet Glorie, on the very edge of explored space. The main military forces protecting the colonists of Glorie from the unknown are the Armies of the Southern Cross.
However, unknown to the human colonists, Glorie is the ancestral home of the Zor, a race of highly advanced humanoids that have been wandering the galaxy for the past few centuries. Although the Zor abandoned their homeworld ages ago, they have now returned with what remains of their fleet to reclaim their planet. Unfortunately, the humans have already made Glorie their new home and refuse to leave it. Since Glorie does not have a large enough food supply to support the humans and the Zor together, they declare war on each other for sole possession of the planet. The resulting war for Glorie basically makes up the Southern Cross TV series. The events focus on Jeanne Francaix (Dana Sterling), the young and inexperienced leader of the 15th ATAC. Jeanne struggles to change her band of misfits and drop-outs into a skilled fighting force, and largely succeeds in turning the 15th ATAC into an elite unit by the end of the war. During the battles Jeanne also grows and matures from a headstrong girl into an experienced woman. (Typical Japanese "coming-of-age" storyline)
The second of the three series that make up Robotech, it did not fare as well as the other two. Running under the full 26 episodes, this is considerably darker than the original Macross. Much more Gundam-esque in its depiction of war, especially in the metaphor of fighting oneself. The animation stands up well for its age and the story is top-notch. A classic series and not to be missed if you like Macross, but the only way to see it nowadays is to get the Robotech Perfect Collection.