Mélanie is too nice. Her mother, her boss, her girlfriends, her neighbour and even her neighbour’s dog know this... and take advantage. One day, after a final humiliation, Mélanie decides to change. From now on, she intends to take revenge on all those who’ve made her life a misery. Except that nastiness can’t be learned in two days, especially when you’ve been a nice girl all your life...