Reiwa 5 (Wa) No. 2 Damages Case

In 2023 (Reiwa 5), a group of South Korean fisheries cooperatives and individual fishers filed a damages lawsuit in Tokyo District Court against the Japanese Government and Tokyo Electric Power Company (TEPCO). The plaintiffs argued that the ongoing discharge of treated radioactive water from the Fukushima Daiichi Nuclear Power Plant into the Pacific Ocean caused reputational and economic harm to the Korean fishing industry, potential health risks, and violated obligations under the United Nations Convention on the Law of the Sea. The case, docketed as Reiwa 5 (Wa) No. 2, sought an injunction against further releases and substantial monetary compensation. The litigation drew international attention as a test of transboundary environmental accountability. Both sides presented extensive scientific and legal evidence during the proceedings, which concluded with a landmark first-instance judgment in 2025.

In 2025, the Tokyo District Court dismissed all claims. The court ruled that the plaintiffs failed to establish a causal link between the water release and specific economic or health damages, and it found that the discharge process met prevailing international safety standards. No injunction was issued, and the claim for compensation was denied.

The core dispute centered on whether the plaintiffs had proven actual, compensable damage directly caused by the discharge. Additional key issues included whether TEPCO and Japan had conducted adequate environmental impact assessments, whether the discharge complied with international safety standards set by the IAEA, and whether the operation violated Japan's obligations to prevent transboundary environmental harm under international maritime law.

The ruling intensified anti-Japan sentiment and triggered renewed boycotts of Japanese seafood in South Korea. It sparked a global debate on the adequacy of international law for addressing long-term, transboundary nuclear contamination. The case also solidified a legal precedent in Japan, making future foreign nuisance claims against state-regulated nuclear activities significantly more difficult.