Fairy Castle is a world where fairies can learn how to use their magic for good. One day, Luna, the Dark Fairy, absorbed all the black magic, which was forbidden, and stole the Fairy Stone. Shirley, the guardian of the Fairy Stone was punished for her irresponsibility. She was trapped inside a music box and sent to Earth, where she landed on a small town in China. Two girls, Maggie and Michelle, find the music box and open it, freeing Shirley.
Shirley grants them magical powers, allowing them to transform into fairies, and together they start their quest to retrieve the Stone.
Source: Balala the Fairies Wiki Fandom)