Najimu Mujina is just your average five-year-old girl—who also happens to be the CEO of Mujina company. While she leaves most of the important work to her secretary Yuki Karuizawa, she often tries to act like a CEO with her inadequate business jargon. But, although her innocent efforts can be unexpectedly kind and uplifting, it just usually adds to the troubles of those around her, such as diligent employee Mayu Warito and her fellow colleagues at Mujina Company.