Kara and Sara, tells the story of Laura, a woman surrounded by poverty, who is forced into a night of prostitution to pay for the medical treatment of her dying mother. Laura becomes pregnant and has twins Kara and Sara, two sisters separated when they were very young, who will take different paths that will confront them.
Laura became pregnant by a married man named Antonio Dela Rosa. Despite what happened, Ismael, who has shown Laura true love, marries her and becomes the father of her two unborn children. On the same day of Laura’s delivery, Lucille, Antonio’s wife, also gives birth to their daughter, Sofia. However, the couple’s daughter dies shortly after childbirth as a result of her premature delivery.
While Antonio and Lucille mourn the premature passing of their daughter, Laura and Ismael enjoy and live a happy life with their twin daughters, Kara and Sara, despite being poor. At one point in the story, when Kara is diagnosed with leukemia, Sara becomes jealous of the extra attention given to her sister. With limited means, their parents are forced to separate them and give Kara to her biological father Antonio, who has the means to provide better treatment for her illness.
Antonio takes Kara to the Dela Rosa Foundation, where he meets Lucille. Discouraged by Kara’s illness, Lucille begins to adopt a mother-daughter relationship with Kara to consider her as her own daughter with the previous loss of Sofia. Unaware of the relationship between her husband and Kara, Lucille adopts and takes Kara abroad where she recovers from her illness.
The two sisters, despite sharing the same appearance, grow up living separate lives and contrasting personalities. Sara, who has a penchant for pageants and beauty contests, grew up with ambition towards her own life and dream, becoming more self-centered and selfish while Kara grew up to be charming, sweet, soft, very sophisticated and artistically inclined.
After fourteen years, an adult Kara returns to her hometown and that’s when we see events unfold that will bring her face to face with Sara.