The Immature (2011) on Netflix

Twenty years ago, while they were 12th grade students, Giorgio, Lorenzo, Piero, Luisa, Virgilio and Francesca were a high-spirited band. Then they graduated, integrated themselves into society and lost track of one another. One day they receive a letter from the Ministry of Education: because of a formal error, they must retake the exam. With the initial shock now past, they grasp the opportunity to meet again, to share laughters and to cram together like they used to. On the other hand, they are not the same persons they were two decades before...