In the year 2199, the Gamilon race declares war on humans, intent on taking Earth for themselves. The fighters on Earth do everything in their might to keep the planet stable, but alien technology proves to be far too advanced, and the resulting destruction renders the surface of planet Earth completely uninhabitable. The underground shelters are also becoming weak, and if nothing changes, humans will become extinct in less than a year. But just when all seems lost, Queen Starsha from the planet Iscandar offers a helping hand. The key to victory lies in the Cosmo-Cleaner D, which can eliminate the radiation that Earth is suffering from. However, the only way to get a hold of this life-saving device is if someone from Earth goes to Iscandar―148,000 light years away―to retrieve it. The problem is, they have less than a year before time runs out. The fate of the entire human race lies in the hands of the crew of a salvaged WWII craft, the Space Battleship Yamato.

On an archaelogical mission to the end of the known universe, Professor Daiba unwitting unleashes an ancient horror from its confines. Five years later the malevolent alien force sets in motion a plan which reunites the various crewmembers of the Arcadia to sail the stars once more as well as bring Tadashi Daiba to meet Harlock for the first time (again). (Source: ANN)

Second season of Souten no Ken: Regenesis.

After conquering the galaxy, mankind has reached its apex and is now on a steady decline. The resources of the universe are diminishing, and around 500 billion humans begin to return home to Earth. Thus begins a war between the various factions of humans for control of the planet. Eventually, an authoritarian government known as the Gaia Sanction prevents the re-population of Earth. Captain Herlock was one of the Elite Wing who was tasked by the Gaia Sanction to defend the Earth. His fleet of ships was unstoppable under his command. However, the Gaia Sanction allows a diplomatic elite to immigrate to Earth, which angers Herlock. He goes rogue and fires upon the diplomats and the rest of his fleet. He decides to unleash dark matter on the planet to make it uninhabitable, but also becomes engulfed in it which immortalizes him. One hundred years have passed, and the legendary Captain Herlock is still at large, with only the Arcadia under his control. The Gaia Sanction continues with their plans for control over the Earth, while hiding its true state. But Captain Herlock is preparing for one final showdown with them, which will determine the fate of the world!