Community currencies have received much attention in recent years as tools for revitalizing local economies and communities. Many community currencies in Japan, however, have been terminated or suspended because of the failure of circulation in certain areas. In this study, we consider the functions and mechanism of community currency circulation. Because community currency is a communication medium that has linguistic functions, we focus on internal rules of local residents, such as local-oriented values and usage habits of community currency. The purpose of this study is to clarify the circulation mechanism including internal rules by combining two different methods: gaming and multi-agent simulation. Our gaming results confirm that the introduction of a community currency causes changes in buying behavior and value consciousness. Such changes include a stronger attachment to local community and greater mutual cooperation. Analyzing a multi-agent simulation in which these findings from our gaming are implemented, we show that the circulation mechanism is a feedback loop that consists of value consciousness, paid volunteers, and the community currency. This mechanism promotes purchasing in the local community.