According to Jean Reno, he decided to play Léon as if he were a little mentally slow and emotionally repressed. He felt that this would make audiences relax and realize that he wasn't someone who would take advantage of a vulnerable young girl. Reno claims that for Léon, the possibility of a physical relationship with Mathilda is not even conceivable, and as such, during the scenes when such a relationship is discussed, Reno very much allowed Mathilda to be emotionally in control of the scenes.