This chapter covers the 50 years from the inception of the Japan Overseas Cooperation Volunteers (JOCV). It explores the growth and diversification of JOCV as well as its expected returns to Japanese society. Stakeholders nationwide made many efforts to establish and develop JOCV, assisted by increasing domestic internationalization. As Japan's economy grew, Official Development Assistance (ODA) was strengthened and the JOCV program expanded. After the Cold War, new destination countries for aid were added, and the types of work JOCV volunteers were expected to undertake became more diversified. In the twenty-first century, globalization and changes in society have led to a demand for more interactive international cooperation and the possibility of contributing back to Japanese society. Originally, JOCV had three missions: to contribute to developing countries, to deepen friendship and mutual understanding between Japan and those countries, and to cultivate an international perspective among Japanese youth and contribute to society. JOCV has a long history of ODA projects involving citizens, and there is potential for a wide range of future social contributions, including promoting Japan's own sustainable development. [For the complete volume, "Japan's International Cooperation in Education: History and Prospects. Education in the Asia-Pacific Region: Issues, Concerns and Prospects. Volume 63," see ED675739.]