Karina arrives to a mansion to work as a governess of a group of singing children, Mari Nieves, Blanca, Carlos, Javier and Santi, known in Spain as "La Pandilla". She must take care of their education, and she decides to use music to teach them. Meanwhile, the record company where the children work is busy with another project. Their biggest star, Marta, is getting ready a song to represent Spain in the Eurovision Song Contest 1971. Carlos, the composer of the song, titled "En un mundo nuevo" ("In a new world") meets Karina in the mansion and starts feeling affection to the girl, something Marta, who is Carlos' girlfriend doesn't like at all.