In 2021, the United Nations launched the UN Decade of Ocean Science under the leadership of the Intergovernmental Oceanographic Commission of UNESCO. Does Japan's legal system for the use of marine areas (Sea Areas Utilization for Renewable Energy Act) adequately meet the elements of marine spatial planning required by the Intergovernmental Oceanographic Commission? In this article, I would like to identify future issues such as ensuring the participation of stakeholders in the establishment of goals and principles, and mapping process.