This article proposes a reflexion on the construction of how adolescent boys construct their self identity. After situating this in the sociopolitical and theoretical context of adolescence, it presents the methodology of a study aiming to understand from inside the adolescence of the boys: a mix of various modes of collection and analysis of data (the collective creation of videos, interactions, focus groups and individual interviews). It points out that for boys the process of growth they live between 14 and 17 years is represented in terms of openings: opening of oneself, opening to others and opening to the world. Adolescence is also lived as a tension of double temporality: a time eminently present and a time turned towards the future. Finally, the ethnography leads to a more specific discussion concerning the male identity. It is proposed to open this concept with the idea of plural subjectivity, an individual and collective process, always in movement and interacting with the sociopolitical context.