Usagi Tsukino is an average student and crybaby klutz who constantly scores low on her tests. Unexpectedly, her humdrum life is turned upside down when she saves a cat with a crescent moon on its head from danger. The cat, named Luna, later reveals that their meeting was not an accident: Usagi is destined to become Sailor Moon, a planetary guardian with the power to protect the Earth. Given a special brooch that allows her to transform, she must use her new powers to save the city from evil energy-stealing monsters sent by the malevolent Queen Beryl of the Dark Kingdom.