Article 76 of the 1982 United Nations Conventions on the Law of the Sea (UNCLOS)  provides a set of rules for delineating outer limits of continental shelves, establishes the Commission on the Limits of the Continental Shelf (CLCS), and entitles the CLCS with the rights to review scientific and technical data and information submitted by coastal States to support the outer limits of their continental shelf and to make corresponding recommendations. The recommendations made by the CLCS are not legally binding, for the UNCLOS merely declares that “the limits of the shelf established by a coastal State on the basis of these recommendations shall be final and binding”. However, the recommendations serve as the foundation in defining the final outer limits. This article, based on subsequent actions of the coastal states to the CLCS’ recommendations, analyzes the validity of the recommendations, and discusses the validity of the decree on the outer limits of the continental shelf in the framework of international law, which is issued by the Japanese cabinet in 2014. It proposes that the outer limits defined by Japan in accordance with its domestic law go against the recommendations of the CLCS, and that Japan takes its domestic law as a defence and fails to fulfill its legal obligations according to the international law. In this way, the decree is not valid for any third country, nor can it be recognized as final and binding by the international community.