Gaspard is a very responsible boy. In fact, he's more responsible that his own parents who are... disorganized, messy, sarcastic, argumentative, absurd and downright mad. But Gaspard doesn't give up: it's up to him to take care of things around the house. Otherwise, who's going to look after Annabelle, his little sister, and Paracetamolle, the monkey who survived the Servais laboratories? He has everything under control. Until the day when he accidentally makes the beautiful Nina cry. Gaspard decides to do everything he can to bring back Nina's smile.