Using data collected from surveys, 32 in-depth interviews, and over 40 hours of classroom observations within an all-boys-all-Black high school, The Brotherhood Academy, this project explores two critical questions: 1) how do schools shape narratives of hypermasculinity and 2) how do these narratives inform Black boys' performance and understanding of what it means to be man? Bridging the extant literatures on masculinities and race, gender, and sexuality, this paper offers a novel theorization of narratives of hypermasculinity that provides a framework for examining the implications of Black boys' internalization of racialized, gendered, and sexualized scripts on performing manhood, which are often rooted in heteronormative, hypersexual, and deviant conceptualizations of masculinity. I find that even within a generally non-contested site for socialization, such as the Brotherhood Academy, which provides opportunities for resistance by bolstering a novel mission and value set rooted in destigmatizing what it means to be a Black man in society, these narratives of hypermasculinity still exist and negatively impact school actors' ability to hold these boys accountable to the school's standards on manhood. These findings reveal the bounded masculinity that gets propagated within school and has implications for Black boys' consequent socialization outside of school contexts.