Marianela has lived most of her life without the love and warmth of a family, but she has not lost her smile, nor her sweet disposition. When her father died, her aunt Freda sent her to a boarding school under the pretext that her mother, Eva, was an alcoholic and unable to take care of her. Over the years, Freda has gradually stolen away most of Eva’s estate.

When her mother tells Marianela that they will finally be able to live together after she finishes high school, Marianela becomes ecstatic; however, Eva dies that same day in an accident, and Marianela has to go and live with her aunt Freda and her uncle Emiliano (her father’s brother) along with her cousins Emanuel, Kristel, Gretel and Axel. There, Marianela suffers mockery and humiliation. Only Emanuel treats her decently and stands up for her, and Marianela cannot help but to fall in love with him.

Ilitia, Emanuel’s fiancée, knows that Marianela is not physically attractive as she is, but her gentle heart and charisma could easily win Emanuel’s heart. So she joins forces with Kristel, Emanuel’s sister, to make Marianela’s life miserable.

Freda decides to take over Marianela’s inheritance, so she forges some documents stating that Eva owed her a large sum of money and Freda becomes the legal owner of everything. Don Maximo, Emiliano’s uncle, is not convinced by this and becomes suspicious of Freda and her devoted assistant Bernardo.

Netty, Marianela’s aunt and Eva’s sister, wants her niece to come and live with her at her boarding house, but Marianela would rather bear the abuse than be away from Emanuel. Netty is saddened by the decision but she learns to respect it.

Freda is jealous of Netty and sends Bernardo to kill her, but he fails in the attempt and more people begin to suspect of her. Gretel, Emanuel’s other sister, feels the death of her uncle Luis Felipe (Marianela’s father) is somehow her own fault. But slowly, through her dreams and memories, she begins to discover the truth. Freda decides to send Gretel away, to stop her daughter from accusing her of being her brother-in-law’s murderer.

Time goes by and Emanuel is starts to feel a strong attraction toward Marianela. The simple fact of imagining them together infuriates Freda, and she decides to poison a box of chocolates and send it to Marianela as a present from Emanuel. Marianela eats them and ends up in the hospital. When she is told that the chocolates sent by Emanuel sent were poisoned, Marianela feels hurt and betrayed, and she decides to go to Spain to live with her aunt Carlota. A few months later, Marianela goes back to Mexico after her aunt Carlota dies under mysterious circumstances and Freda turns out to be her only heir.

But the Marianela who went to Spain is not the same girl who now returns to Mexico. She is filled with optimism and self-confidence, determined to unveil the truth and get back what is rightfully hers.