The friendship between a little mouse who didn’t want to become a dentist and a big bear who didn’t want to become a notary. Ernest, is a big bear, who is starving and has a nasty cold to tops things off. One day he is looking through garbage to find something to eat and just when he’s ready to put the first thing he finds into his mouth, a piercing cry rings out! “Stooooppp!”. The little mouse he was going to swallow pleads: “if you don’t eat me, I will give you whatever you want most in the world! And it will be better for your health than all this crap.” And this is how Célestine, while trying to save her own life, turns that of Ernest upside down. From these unfortunate circumstances a friendship grows, fought by the world of mice (the upper world) and the world of bears (the underworld) but in vain: together Ernest and Célestine will conquer all prejudices.