Izumi Sawatari and her younger sister, Mitsuki Sawatari, have fled their home and are looking for work. The only occupations available are as maids in the house of Yoshitaka Nakabayashi, a 14-year-old billionaire. What appears to be straightforward job quickly turns out to be considerably more than the ladies bargained for when they discover Yoshitaka to be an authoritative boss who insists on being addressed as "Master."