Laurent is starting a new business: he has decided to shoot a horror film that he will then sell online. Thomas' parents' chalet, a remote place in the mountains, would be the ideal setting. The problem is that they don't want to hear about it. It doesn't matter, the film will be shot in the apartment of Yann, a new friend, who knows everything, who has seen everything, and who annoys Thomas to the highest degree...
Aude is on the verge of a nervous breakdown... Between her henpecked father and her psychorigid mother, she's suffocating! So when she sees Cédric for the first time on his motorbike, hair blowing in the wind... she completely cracks. He's her great breath of freedom! Like a hurricane, love carries them both away! For Cédric, Aude would do anything...
Thomas and Julia learn at his own expense that girls are sometimes mistreated. He decides to campaign in a feminist association and goes there in Julia. What a surprise to discover that his mother is part of this association and never stops complaining about three men who are poisoning her life. Thomas concludes that his mother is talking about Justin, his father and himself who are supposedly the worst machos! War council among the men of the family who decide to make an effort before it is too late...
In two days, it's the "En avant la Sic-Mu" festival! Thomas brings everyone into the adventure. Writing the lyrics, composing the music, rehearsing, it's a total blast between the girls and the boys. Until Marc and Laurent bring back Nath and Aude's stage costumes. Mini-skirts and ultra-low-cut tops! It's a clash. Out of the question for the girls to play the "Barbie-potiches"! Since that's how it is, they'll both sing. The war of the sexes has been declared! Even Thomas can't stop it and has to run from one group to another.
Nothing is going well at home. Indeed, for the first time in his life, Justin is in love. Her name is Marie and she is crazy about extreme sports. Thomas decides to help Justin because he is his little brother, and especially because he negotiated 318 rounds of washing up if the operation "Make Marie fall into Justin's arms" is successful...
Thomas sees another “troublesome” year looming between his absences from school and the appearances of his female double. So he decides to solve the problem once and for all by creating fake parents for Julia! With Marc’s help, this crazy project gradually sees the light of day: first of all thanks to an unemployed actor ready to play Julia’s father, whom the two friends recruit through a classified ad, then, thanks to Aude’s cousin, who lives in Marseille, but who, following sentimental and financial setbacks, is currently squatting in Aude’s room...
Thomas offered Ally, for her birthday, a day in a beauty salon. And of course, by transforming into Emmanuelle (his female double), he will accompany Ally. The dream! However, a major problem arises: Thomas can no longer transform into Emmanuelle!!! A genetic “bug” assures Justin, his little brother who has decided to help him. Over the course of attempts to stabilize his crazy metabolism, Thomas undergoes increasingly bizarre transformations, until he transforms into his own mother!!! Fortunately, this last transformation allows him to discover his mother's plan, to send him to boarding school.