Studies informed by poststructuralist theories of language have examined the relationship between language teachers' emotion labor, identity, and agency. However, research has not yet explored the relationship between emotion labor and volunteer teaching, which is an important practice in language education. Our research seeks to address this gap, drawing on a 2-year qualitative case study at the community-based Vancouver Bangla School (VBS). With emotion labor and investment as the conceptual underpinnings, our study investigated how the VBS heritage language (HL) program structured the emotion labor of seven volunteer teachers, what the feeling rules associated with the VBS program were, and the extent to which volunteer teachers' investment in HL education helped them manage their emotion labor. Data sources included participant classroom observations, field notes, focus group and interview transcripts, questionnaires, and educational resources, which were analyzed using reflexive thematic analysis. Findings indicate that the emotion labor of volunteer teachers was structured by the following characteristics of the VBS program: lack of funding, poor organizational structure and teacher recognition, challenges of online teaching, insufficient number of teachers, limited parental support, and lack of training. This emotion labor was associated with four feeling rules implicit in the VBS program: (a) be generous and caring, (b) be committed and dedicated, (c) be a good and efficient teacher, and (d) have limited expectations of the community. Findings suggest that teachers' investment in Bangla as a mother tongue in multicultural Canada, and their investment in promoting the children's transcultural identities, was particularly powerful, and enabled the volunteer teachers to navigate and manage their emotion labor. The study suggests that an enhanced understanding of a language teacher's investment in a program, institution, or community might provide insight into the important relationship among desire, agency, and emotion labor.