Balala the Fairies: The Mystery Note

The Queen of Fairy Castle gave Shirley a precious music treasure box on her birthday, which contains a mysterious musical gem.
Queen Halle sent her son, Prince Omar disguised himself as a human to steal the gem. Halle used these musical gems to strengthen herself and take revenge on the Fairy Queen. In the face of strong enemies, the fairies once again worked together, and finally they defeated the evil with the power of justice and maintained the peace of the Fairy Castle.
(Source: Balala the Fairies Wiki Fandom)