Celestine is a little mouse trying to avoid a dental career while Ernest is a big bear craving an artistic outlet. When Celestine meets Ernest, they overcome their natural enmity by forging a life of crime together.

Ernest and Celestine are travelling back to Ernest's country, Gibberitia, to fix his broken violin. This exotic land is home to the best musicians on earth and music constantly fills the air with joy. However, upon arriving, our two heroes discover that all forms of music have been banned for many years - and for them, a life without music is unthinkable. Along with their friends and a mysterious masked outlaw, Ernest and Celestine must try their best to bring music and happiness back to the land of bears.

Ernest is a big bear from Charabie. He likes playing music and eating marmalade. He lives with Celestine, a little orphan mouse, and they share his house. Our two friends never get bored! When the first snowflakes start to fall they need to prepare for Ernest’s hibernation: they must take care of Bibi, their wild goose, who will fly away before the big winter, prepare cakes for Ernest and go to the mice’s ball to celebrate the first day of winter.