This study aimed to evaluate the significance of group supervision to Yogo teachers in Japan, who often deal with work-related problems in isolation. Like school nurses in the United States, the role of the Yogo teacher is to oversee students' health education and management. In this study, eight Yogo teachers, each with a minimum of six years' experience, attended six supervised group sessions in 2016. During each session, one participant presented a case, and all participants then engaged in a general exchange of opinions about the case. Following the six sessions, semi-structured interviews were conducted with the participants, and the interview data were analyzed using M-GTA (modified grounded theory approach). The results generated 14 concepts and six categories, schematizing the Yogo teachers' change of consciousness in relation to each category. The Yogo teachers evidenced needs in the categories of "Emotional Support," "Awareness," "Systemic Thinking," "Collaboration," "Motivation Improvement," and "Training Location." Ultimately, the study demonstrated that supervision by family therapists improved education by enhancing Yogo teachers' consultation abilities and systemic thinking. Yogo teachers' participation in the group supervision resulted in the following change in consciousness: their awareness was deepened by receiving emotional support, by training with the intent to learn, and by considering the significance of collaboration. Overall, teachers experienced an increase in self-motivation. The process for "Improvement of consultation ability" also became clear. Thus, group supervision by psychiatrists and/or family therapists has a positive impact on the overall motivation and work efficacy of Yogo teachers in Japan.