The policy-making structures that govern Japan's official development assistance (ODA) incorporate the Japanese private sector to a greater degree than is commonly supposed. Apart from explaining the limitations that the Ministry of Foreign Affairs faces in setting substantive policy in ODA, this article indicates how mechanisms of private sector inclusion facilitate public-private sector collaboration, and how these mechanisms are integrated into a system of policy formulation and implementation. The system is rooted in the mid-1950s to early 1960s when expanding Japanese private sector activity in the developing world was a key state objective. Under bureaucratic guidance Japanese still operates a system of intimate collaboration between the state and private sector in ODA. The dilemma of the private sector today, however, is that while it how wants to reduce the autonomous power of the bureaucracy, it does not want to lose the benefits of privileged access to ODA resources that the status quo system provides.