In Casi Treinta, the 29-year-old Emilio (Manuel Balbi), a rich employee of an airline who wants to be a writer, finds his new love in the 18-year-old Cristina (Eiza González). They break up after Emilio becomes absorbed by his job when he receives a promotion. Eventually, Emilio becomes engaged to a woman of his own age, Lucia, but he may not be entirely satisfied.