Long ago, there were powerful creatures living in the earth above humans. They were called the kwamis. They grant wishes to the people but due to abusing of power, they decided to hide from the human world.
Currently, they were living in the palace with the emperor disguised as noblemen so they will be safe from threats and only few human being will be able to interact with them.
Each kwami has a jewel called miraculous. Once it's destroyed, they will also vanished from the human world. There are two jewels that grants ultimate power, the earrings of the ladybug and the ring of the black cat. Only they can get from the kwami that is wearing it.
Due to the knowledge of the owner of the ring about the ultimate power, he was banished from seeing the owner of ladybug earrings so he will not get the earrings for himself but he never gave up and still searching for the other half.