The beautiful Esperanza is a super featherweight fighter, who is forced to leave the boxing ring after an unexpected injury. She decides to look for a new job to support her good-for-nothing boyfriend Quique and his mother. In her search for work, she arrives at the Quesada company, owned by the handsome Martin. The two share a chance encounter and fall in love at first sight. A widower, Martin has abandoned his love for car racing following the tragic death of his wife, and is about to remarry the ambitious and frivolous Constanza. Martin decides to hire Esperanza as his personal assistant and she gradually becomes an integral part of his life, especially after he decides to adopt three homeless siblings. The two will face insurmountable obstacles on their way to true happiness, as Constanza and Quique will do their outmost to keep them apart.