The article is an empirical study which is to contribute to developments of Japanese regional cooperation. The study includes the analysis of two European cases, "The Baltic Sea Cooperation", "Trakia Cross-Border Cooperation", on the assumption that insights from these cases can be applied to Japan. In terms of methodology we refer to the Multi-Level Governance perspective, namely the theory for the European regional governance which is focusing on the cohesion policy or the regional diversities.
Both cases which are Cross-Border Cooperation have two peculiarities. One is that each actor who participates in the cooperation has the equivalent and cooperative relationship with the others in the cooperation network. The other is that the "Centrality" plays the pivotal role for sustaining this relationship mentioned above.
The further analysis on two cases suggests the "Networked Polity", "which is functionally and territorially disaggregated, but nevertheless linked together and linked to society through a web of interorganizational and intergovernmental relationship", as the ideal model of the regional cooperation. In conclusion, we explore the possibility of "Networked Polity" in Japan.