The story takes place in the outskirts of Mexico City in Bordo de Xochiaca (a landfill), where a girl Esmeralda 12 years old who is always “disheveled and dirty” like a “Stray Cat” (una “Gata”). Esmeralda is a young neighborhood girl who grew up without her parents and learned to be happy with what little she had. She was raised from childhood by an elderly woman named Mrs. Rita who exploited her by making her go ask alms, sell candy and newspapers.
Esmeralda could neither read nor write. She meets Pablo Martínez Negrete, a high society rich boy who teaches her to read and write and with whom she becomes friends. Since then Esmeralda notices that he is the first person to call her by her name and the first person who really truly cares about her. But Pablo’s mother opposes his friendship with “The Stray Cat”.