A princess tries to stop a war between worlds. Someone shoots her down anyway. Everything that follows is the show punishing you for thinking diplomacy could matter in a world built on military advantage. Inaho doesn't have superpowers or a fancy mecha, he has a calculator and the willingness to break the rules that everyone else still believes in. The show dismantles the idea that a good person with good intentions can survive a system designed to crush them. By the time the first season ends, you understand why the second one exists, and it's not because anyone won.

A hypergate found on the moon in 1972 opened the way to Mars. The humans who settled there uncovered an advanced technology they called Aldnoah, founded the Vers Empire, and went to war with the Terrans who stayed on Earth. A battle known as Heaven's Fall destroyed the gate and shattered the moon, forcing an uneasy ceasefire. Fifteen years later, Princess Asseylum of the Vers Empire comes to Earth hoping to mend relations between the two worlds, and high school student Inaho Kaizuka witnesses the plot to assassinate her. The truce collapses, and Martian soldiers riding giant steel machines descend from the sky. Facing an overwhelming enemy, Inaho and his friends must fight the Vers Empire to end the war. The result is a mecha action series set in a science fiction war between two planets.