Hyper Defense Unit member Anna Yuki is a crucial warrior who transforms into a giant fighter, defending Earth from alien and monster attacks. However, the Gibra aliens plot to capture her in order to seize a high-energy entity hidden deep beneath the ground, aiming to dominate Earth. The Hyper Defense Unit detects this energy source and rushes to the site, but Anna is ambushed and captured by the Gibra aliens. The true nature of this energy source? It holds the key to the complete resurrection of Emperor Giga, the disgraced ruler who once sought to destroy Earth. Intense battles erupt across the city, energy is forcibly drained from Anna’s chest and groin, and the battered Hyper Mammy appears with her chest emblem flashing red! Facing the worst possible outcome, Hyper Mammy must rise to stop Giga’s revival!