Mao Onigawara is eight years old, cheerful, and the granddaughter of the chief of staff of Japan's Ground Defense Force. When adorable extraterrestrials begin invading the country, the military faces an odd problem: these creatures are far too cute for ordinary armed forces to handle. Enter Mao and her two best friends, who happen to be the granddaughters of the Air and Marine Defense Force chiefs. Mao carries a cloverleaf-shaped badge that lets her transform but grants her no special powers at all, and together the three girls take on the job of defending Japan from the cute invaders. The result is a short-format comedy that mixes magical girl trappings with science fiction.