María Hernández, a humble and uneducated dreamer, lives with her godmother Casilda on the outskirts of Mexico City and works as a picker of recyclable materials in a landfill. On María’s 15th birthday, her godmother dies and asks Father Honorio to find a place for María to work and live. María is welcomed by Fernando De la Vega, a wealthy and influential businessman, who teaches her manners and treats her as family. However, his wife Victoria and maid Carlota despise María upon meeting her.

Luis Fernando, the eldest son of the De la Vega family, is dumped by his girlfriend Brenda and vows to avoid emotional involvement with women, choosing instead to toy with them. He initially engages with María for this purpose but ends up falling in love with her. Soraya Montenegro, Victoria’s boastful and proud niece, is in love with Luis Fernando and wants to marry him. She despises María and calls her “marginal.”

María gradually earns the friendship and trust of the mansion’s residents and staff, including Victoria, who changes her attitude, Lupe the housekeeper, and the younger De la Vega children, Vladimir and Vanessa. Soraya exploits a drunk Luis Fernando, takes him to bed, and presents a fake pregnancy test, forcing him to marry her despite his love for María. To forget Luis Fernando, María dates Vladimir and takes etiquette classes from Doña Caro, hired by Don Fernando. Luis Fernando matures, stops drinking, and starts working at his father’s company. He becomes suspicious of Soraya’s pregnancy, and she then claims to have had a miscarriage.

Soraya moves into the De la Vega mansion with her nanny, Calixta, who has cared for her since childhood. Soraya frequently fights with María and wants to kill her. Calixta, who is a healer, helps Soraya by putting poisonous weeds in María’s water, causing María to fall ill and be hospitalized. María discovers the cause of her illness. Calixta reveals to Soraya that she is her real mother, leading Soraya to angrily kick her out of the mansion. Soraya’s lover, Osvaldo, learns of the evil plan and threatens to expose her unless she pays him. In a violent altercation, Soraya tries to kill Osvaldo but ends up falling from a window and is presumed dead. Meanwhile, Luis Fernando and María plan to marry, but a jealous Vladimir decides not to attend the wedding.