In a distant future where humanity dwells underground due to constant threats, two young men, Simon and Kamina, live in a village rocked by chaos. When their home collapses and a colossal 'Gunmen' emerges along with the skilled Yoko from above, their fates intertwine. United, they pilot the unearthed mecha 'Lagann' towards the surface, only to confront a harsh reality under the tyranny of the Spiral King and his beastmen. Determined to forge a brighter tomorrow, Kamina, Simon, and their allies take on the Spiral King to bring hope to a world shrouded in despair with the power of Gurren Lagann!