A shy kid pulling a robot head out of the dirt becomes a man screaming his way through galaxies because someone believed in him first. The show builds so fast you can't catch your breath, then hits you with a moment of genuine tenderness before launching into something twice as big. By the end you're not watching a mecha anime anymore, you're watching a sermon about the power of refusing to accept limits, delivered at maximum volume.

Simon spends his days digging through rock in the depths of an underground village, a timid boy without much ambition. His friend Kamina is a brash dreamer with wild confidence, convinced that a world exists beyond their cavern ceiling, and he wants to break through and reach it. While digging, Simon turns up a small glowing drill that proves to be the key to an ancient machine, a robot the pair name Lagann. When the ceiling caves in and a giant enemy robot crashes into the village, Simon and Kamina fight back with Lagann, helped by Yoko, a gun-toting girl from the surface. With the sky now open above them, the trio heads out into the wastelands, where they join other survivors against the Beastmen, humanoid creatures whose war machines, called Gunmen, terrorize what remains of humanity. Mixing mecha action with comedy, drama and romance, their fight to reclaim the surface gradually draws them toward a far larger mystery.