During France's belle époque before World War I, elegant cars, mansions, and servants defined the lives of les grandes horizontals, the courtesans of kings and millionaires. One of the most successful, Lea de Lonval, is approaching a certain age when an older associate, Charlotte Peloux, asks Lea to take on her 19 year old son, whom Lea has called Chéri since he was a child. They become lovers and, to their surprise, the relationship lasts six years. When it ends abruptly with a marriage his mother arranges to the daughter of another courtesan, Lea finds herself miserable. Has she fallen in love? If so, do she -- and Chéri - have any choices?