Against the dictatorship of a thin and perfect body. The mouse Moussy, with a slim figure, is at the Opera to take the little rat contest. The Fluettes sisters, ill-intentioned mice with ultra-thin waists, point out to her that it will be difficult to pass the contest without losing weight. Moussy, influenced and destabilized, goes on a diet until she stops eating and loses all her strength. Fortunately the VSS, the Old Wise Mouse, watches over Moussy...

Moussy, the little dancing mouse, is confronted with the dictatorship of brands and the "disposable" fashion. She can't afford to be like her friends who go on a shopping spree. So how can she be stylish without spending a penny? Her pugnacity and the advice of the VSS, the Old Wise Mouse, will enable her to find THE solution. Once again, she will triumph while getting her friends to change their dress code.

How to turn your faults into qualities Moussy is a plump little mouse who is a broom attendant but dreams of dancing in the opera. When her mouse friends advise her to give up because of her looks, she starts to cry. Then VSS appears: the Wise Old Mouse. She knows everything and solves the most complicated problems. She will help Moussy to take advantage of her looks and teach her that "a defect can become a quality, it's only a question of will"...

Moussy, a little mouse dancer, and her friends travel to London to dance their ballet at the Royal Opera House. A great opportunity, they think, to visit the city! The only problem is that no sooner have they arrived than their dance teacher is kidnapped... Our mice then set off on a real treasure hunt through London. Will they manage to find him and save their show?

How to overcome fear and not give in to blackmail. We find our little mouse Moussy, now a little rat at the Opera, who has just been chosen to dance a ballet alongside the star dancers in a custom-made costume, what a stroke of luck! But an evil ghost gets in the way. He scares her, threatens her and forbids her to get her costume back. Moussy, terrorized by this ghost, is desperate. She knows that without her costume she will not be able to go on stage. Will she really let her chance go? But the VSS and its lessons of wisdom are not to be counted on...