Milk‑chan lives in a house perched on the side of a building, accompanied by two quirky sidekicks: Tetsu‑ko, a paranoid robot that resembles a bottle, and Hanage, a green blob sporting a moustache. Struggling to pay rent, she even attempts to extort a local ant family, an effort that ends in failure. Her fortunes change when the president himself offers her a secret mission. When she answers the phone for her assignments, Milk‑chan quips, “Hello, Bank of Hokkaido. Just kidding!” After receiving the brief, she and her companions launch the “Milk‑6” helicopter to undertake the task. The series parodies 1970s spy thrillers.