Meet Mao Onigawara, an energetic 8-year-old student who happens to be the granddaughter of the Chief of Staff of the Ground Defense Force. With her unique cloverleaf-shaped badge that grants no special abilities but allows her to transform, Mao joins forces with her best friends, who are also granddaughters of high-ranking officials, to protect Japan from an invasion by adorable aliens. These 'cute aliens' pose a threat beyond conventional military means, requiring a special kind of defense.