Fujido Oriko heads the Fujido Zaibatsu, which holds a monopoly on Japan's vending machine business, and she has spent years building up the city her father gave her as a small child. Her eccentric butler, Dr. Sebastion, is always close by. When a huge monster attacks the city, he hands her an experimental energy drink from his research team. Almost at once she grows to a colossal size, matching the kaiju and rising above the skyscrapers. She struggles at first but drives the invader off, and each time a new threat appears she becomes a giant again to defend her city. The series blends action, comedy, fantasy and sci-fi with an ecchi streak, and much of the fun lies in whether Oriko can protect everyone while keeping her dignity intact.