Since the day their mother Aline remarried, Patrice and Eric, a joyful pair of twins, have been very happy. Indeed, François Chantour, their stepfather, is very kind and behaves like a big brother to them. Even if they are not very rich, the four of them live a cheerful life in their charming house. The trouble is that, in Lyon, the family on the boys`father`s side are worried, especially the twins` grandmother, who fears Patrice and Eric are given a bad education. She therefore brings them to her big house in the hope of their improving their manners.