Gurren Lagann

Born and raised in a secluded underground village, Simon and Kamina have only heard tales of the surface world. Kamina, the more adventurous of the two, dreams of making a mark on the world, while Simon lacks confidence and clear ambitions. Their lives take a dramatic turn when Simon, during one of his digging expeditions, discovers a mysterious object. This object is revealed to be the key to an ancient war artifact, which they name Lagann. Armed with Lagann, Simon and Kamina, alongside Yoko Littner—a fiery, gun-toting redhead from above ground—successfully defend themselves against an unexpected attack from surface dwellers.

The battle leaves the sky wide open for the trio to see, inspiring them to venture out to the surface. There, Simon, Kamina, and Yoko encounter the Beastmen, hostile humanoid creatures piloting robotic suits known as Gunmen. Despite numerous challenges, the trio, along with other survivors, courageously battles these foes as they journey across the surface, driven to reclaim it and solve a mystery of cosmic proportions.

[Adapted from MAL]