This research puts its main focus on the dynamic process of inclusion and exclusion in adolescent peer groups in the school context. Peer groups are constructed as fluid and dynamic small groupings of friends, which relate to one another, forming relationship nets. In this dynamic process, adolescents have to fit in and be accepted. This does not always occur successfully because the same group which functions as a binding element, may also promote exclusion. In this sense, the research aims at listening to adolescents not only about the dynamic formation of those groupings, but also about inclusion and exclusion processes. This ethnography-based study allies a socio-historical perspective on identity construction in which identities are constructed within a social, cultural and historical context, with a focus on the analysis of narratives in interaction. For the analysis of narratives, this research uses Labovian categories flexibly, namely, evaluation. It also observes narrative/identity performance with a focus on evaluation and that observation is based on the positioning approach to narrative analysis, which allows for the analysis of the ways individuals position themselves in relation to their identities and the identities of their interlocutors. The research frames the small community studied here as a microcosmos which gives rise to a local perspective as well as intelligibility about issues concerning youth culture, especially those concerning the processes of inclusion and exclusion that take place within the dynamics of adolescent peer group formation in school.