In this paper, we focus on gendered themes promulgated in three books written in diary cartoon form. Although written for different audiences, each of these books constructs gender norms in similar ways. They promote heteronormative gender roles for boys and girls by endorsing traditional femininities and hegemonic masculinities through the following themes: popularity, mean girls/bullying, self-concept and self-esteem, friendship, and adult naivete. First, we discuss the ways in which gender is implicated in children's literature. Then, we describe and analyze the diary cartoon books, contrasting and comparing those with girl protagonists and that with a boy protagonist. Finally, we explore the gendered implications in the books' themes, concluding that girls and boys are represented in different manners that reinforce gender essentialism and heteronormativity.