Proponents of character education claim cultivating virtues during schooling helps students, schools and society flourish but critics argue character education programs implicitly justify social inequality by assuming success or failure in life is due to individual character. There is little empirical research about which individual factors, such as gender, or contextual factors, such as school type, may affect secondary school students' character. This article begins to address this with a comparative case study of moral reasoning within and between two different secondary schools in Mexico -- a public co-educational school and a private girls' school. Results suggest individual differences (gender, religion, family circumstances and socio-economic status) and school (moral education program and school ethos) may relate to students' ability to make moral judgements in response to realistic moral dilemmas. We consider these findings, focusing on how gender, religion and school-type may impact on adolescents' moral reasoning.