Rosa is barely twelve years old when her older cousin, Tina, is orphaned and is forced to share a room with her. After the hasty move, Rosa soon realizes that her cousin represents everything that she does not tolerate; Tina is an irresponsible, ungrateful and troublesome girl. But, little by little, Rosa will begin to realize that behind the things that repel her from Tina there is something hidden that she longs for herself: to be an extroverted, overwhelming and sexy young woman capable of altering the daily life of the Mediterranean town in which they live. It will be precisely these differences that will determine the course of their adolescence, a time when naivety and maturity are so crudely mixed. A clash of mentalities that will be completely unleashed with the arrival of the Montsó family to the neighborhood.

La Prima Mayor, which translates to The Older Cousin, chronicles the awakening of a girl as a woman with the clarity and narrative intelligence typical of a Goya-winning screenwriter. For the cover design, the publisher requested a candid recipe set against the warm colours of the Mediterranean. Rendered as Barbie dolls, the two cousins can be seen swimming in the turquoise waters of the Meditteranean Sea in a path of an inevitable collision. While Tina is wearing a striking red bikini and confidently floating on her back, Rosa is wearing a plain, full bathing suit as she swims with her stomach faced down, capturing her timid nature.