South Korea lodged a diplomatic protest after Japan held its Takeshima Day event on 22 February 2026 in Shimane Prefecture. The disputed islets, Takeshima to Japan and Dokdo to South Korea, lie in the Sea of Japan (East Sea) and consist of two main islets, Dongdo and Seodo. South Korea has controlled them with police since 1954. The waters are rich in fish and are thought to hold gas hydrate reserves.