Casual Day is a company practice imported from the USA. Every Friday the workers are asked to exchange their suits for more informal attire. Ruy has always lived as he liked. Though clever, he's gotten himself into a jam. José Antonio, his girlfriend's father, has earmarked an important job for him in his company. He wants him to be his successor. At the age of 25, without actually having decided anything, he's trapped. He'd like to say no to the job, to José Antonio, to Inés, his girlfriend, and to the Casual Day stuff. But it's not easy to say no. What started out as a simple event, a weekend in the country, ends up deciding the rest of his life.