Two hundred years of buried weapons is enough setup for any war story. Orguss 02 doesn't spend time explaining why they matter. It shows you a world already collapsing under the weight of them, soldiers and civilians both drowning in a conflict neither side controls anymore. The Decimators aren't MacGuffins to fight over. They're inevitability made metal, and everyone watching knows it. This OVA moves like it's already lost, which is exactly why it grips you.

The rival nations of Zafran and Revillia slide from years of mistrust into open war, and each turns to the Decimators: colossal ancient war robots that nearly wiped out all life on the planet 200 years earlier. As both armies dig up and reactivate more of these machines, innocent people are pulled into the fighting and neither side's leaders will back down. A young cadet named Lean and Nataruma, a young woman with psychic gifts, form a desperate plan to change what happened two centuries ago, hoping it can save humanity from total destruction. The result is a six-episode mecha OVA mixing adventure, science fiction and giant robot warfare.