Esmeralda, whom everybody calls “The Stray Cat”, grew up in a suburban slum under miserable conditions; ever since she was a little girl she has lived with Doña Rita, who exploits her by sending her out on the streets to beg or sell candies in order to “earn her food and bed”. As a child, she became friends with Pablo, a wealthy child who cares for her and tries to help her behind his mother´s back, Lorenza, who looks down on “The Stray Cat” due to her social prejudices which make her reject poor, uneducated people.
Esmeralda has turned into a beautiful woman over time and although she is still very poor, she has managed to always look pretty in front of Pablo. They have grown together, but Pablo has problems with noticing that he feels more than just affection for her. Once he accepts it, he confesses his love to her and tells his parents that he will marry Esmeralda as soon as he is financially stable to provide for her. Agustin, his father, pretends to agree with his son´s plans. Nevertheless, he does everything he can to keep him from getting a job. On the other hand, Lorenza tries to make him feel interested in Monica, a rich young girl, so that he can forget about “The Stray Cat”.
Agustin persuades Pablo to study a master´s degree abroad with the excuse that it would be easier for him to get a job there and then marry Esmeralda. Pablo has no idea about the intrigue behind this proposal and accepts. Although Esmeralda feels hurt by this decision, she contents herself with it, trusting Pablo´s parents too. In spite of everything, Esmeralda and Pablo fight for their happiness and secretly marry before he leaves. Some time later, Esmeralda realizes she is pregnant and even though she tries by all means to communicate with Pablo, his parents and Doña Rita prevent the couple from getting together again. Agustin raises doubt on Pablo about Esmeralda’s integrity, making him believe that she has cheated on him and is now with another man. On the other hand, they make Esmeralda believe that Pablo has dumped her.
Esmeralda only counts with “Jarocha”, a woman who loves her very much and has always protected her from Doña Rita´s abuse; and with Fela´s unconditional love, a crazy woman who came to live in the slum and with whom she immediately hit it off. What Esmeralda ignores is that this crazy woman is in fact her mother, Blanca, who went mad after her daughter disappeared and her husband was send to jail, Fernando de la Santa Cruz, who was accused of killing a man and sentenced unjustly for acting in self-defense. He was condemned due to the dirty tricks of his lawyer, and while he was in jail they made him believe that his wife and daughter had died. The truth is that Esmeralda was stolen and delivered to Doña Rita on Agustin´s orders, the same man that put Fernando into jail.
The long-awaited day comes and Esmeralda gives birth to her twin children; however, she doesn´t imagine that it is right then when her agony will begin. Doña Rita, who always sees for herself only, pushes her to marry “The Italian”, a low-class man that she considers to be rich but who is nothing but a man obsessed with buying Esmeralda´s love. She seems forced to accept his marriage proposal since her kids get seriously sick and she sees him as her only solution.
Finally, present and past meet again. Fernando has been released from jail and swears to take revenge against those who have hurt him. Pablo gets back to the country ready to marry Monica, believing Esmeralda has betrayed him. Esmeralda’s life will change radically, but for the love she feels for Pablo,“The Stray Cat” will have to use her strong and rebel character in order to fight for what she really loves; because she is a woman of one love.