The series follows Esperanza's search for her real family. It seems that Esperanza's mother, Isabel, and father Juan Salgado, got married without the approval of Isabel's mom. To be together Isabel refused to marry the man her mother promised her to, Jaime Elustre, and Juan left the girl he had been dating at the time, Sandra.
As the years went by Isabel gave birth to three kids, two daughters and a son. One day Esperanza's mother took her, her sister, and brother on a bus trip to visit someone. Due to a bus accident, they got separated and had Juan believing all of them to be dead. (Source: Wikipedia)