Les Tuche, a modest French family, sees their life change after winning 100 million euros in the lottery. Thanks to money from his parents, the youngest of the brothers, Donald, known as "Coin-coin", goes to Los Angeles for a month to improve his English. On the campus of the University of Los Angeles, he meets Jennifer, the daughter of the famous American financier Ron Carrington. Donald, impressed by this family that is the opposite of his own, feels compelled to lie about the Tuches, convinced that the two families will never meet again, until the day his family decides to make the trip for his birthday, without saying anything.