María Belén is the story of a six-year-old girl who has recently lost her adoptive parents in a tragic accident. He has stayed with his uncle Rogelio, an ambitious and evil man, who planned said accident to take over the inheritance of his half-brother Alfonso García Marín... but did not take into account the possibility that María Belén would emerge unscathed from the catastrophe and, much less, that she would be the universal heir to Alfonso's assets. That is why now Rogelio has to hide the girl to achieve his goal.