Many rural areas face difficulty in how to motivate farmers to embark on diversified activities, such as tourism, while raising managerial efficiency. Thus, this paper conceptually and empirically evaluated how a farmer's identity correlates with managerial efficiency since the connection between the two has not been explored fully. We have addressed this issue through examining farmers' efforts in providing an emerging new educational tourism service by focusing on the Educational Dairy Farms in Japan. Conceptually, this paper classified farmers' identity into two types: traditional identity as a simple farm producer offering an educational service as a volunteer, and, enlarged identity, which is oriented toward viability of a new service activity. Empirically, data envelopment analysis revealed that those with the enlarged identity realized a higher managerial efficiency although there was much room for improvement in overall managerial efficiency. Consequently, support measures with a wider perspective that include identity issues should be designed for capacity building of farmers who are conducting tourism.