Fernando Gonzálezis the son of a wealthy Spanish noble family, and all his life he has been pampered and spoiled. This resulted in Fernando's petty, malicious personality. Fernando finds Nadja very attractive (in a snotty rich kid way) but instead of being nice to her, he bosses her around and publicly humilliates her by forcing her to attend a masked ball as an entertainer. He also blackmails Nadja into attending another ball. His family also happens to be the one that employs Rosemary after she leaves the orphanage. Rosemary has a huge crush on Fernando, but his mean attitude towards her is one of the things that causes Rosemary's startling behavior.

Source: Wikipedia