Én és a kisöcsém (1989)

Kató Kelemen is asked by her father to go to his office and welcome an important business partner of his. When Mr. Andersen arrives he assumes Kató is a secretary and instructs her to deliver a letter. He's about to travel to Venice with his nephew who he has never met before. Since Kató falls in love with Andersen at first sight, she decides to dress like a boy and pretends to be the nephew.