Students' emotional engagement in classrooms has always been regarded as a crucial factor influencing educational outcomes. Emotionally-engaged students are highly motivated to attend classes and participate actively in discussions. Conversely, emotionally-disengaged students are habitual truants and/or often misbehave in classrooms. It is time consuming to conduct research using traditional methods such as data collection or questionnaire. Furthermore, as these experiments are conducted on humans, limited settings can be organized and difficult to control/monitor. Therefore, in this paper, we present our work in-progress addressing to the problem. We propose a conceptual emotion-based model that is animated by an agent-based social simulator. The rudimentary theory of this proposal is based on three main elements; the engagement level of students, the emotional state of a lecturer and the emotional state of students in a classroom.