The much-anticipated South Korea-China-Japan summit is expected to be held in Seoul, raising high hopes for a renewed vision of regional peace and prosperity. However, achieving sustainable relations requires collaboration among multiple entities beyond the central government level. In particular, strengthening the foundation for exchanges and cooperation between local governments in all three countries is crucial. This session will bring together leaders of Jeju, Okinawa, and Hainan to share their achievements and visions in promoting peace and prosperity through subnational diplomacy.