Abstract This article explores the question of overlap in unfair competition law in Japan and Korea and discusses whether the introduction of a general clause could address the problem of overlap. Positive laws regulating unfair competition in Japan and Korea have adopted a similar set of rules based on specific conduct regulation, with some variation. Notably, Korean law now prohibits the unfair use of another’s achievement based on an open clause, complementing the specific list of prohibited conduct. The article first presents an overview of unfair competition law in Japan and Korea, highlighting the requirements for protection and limitations, and then explores the problem of overlapping claims surrounding data misappropriation. Contrasting the legislative techniques used by Japan and Korea, this article notes that an open norm may provide the judiciary with an interpretative tool to dynamically address emerging unfair conduct. However, as there is a danger of limiting free competition and potential internal inconsistencies, to avoid asymmetric convergence, open norms should be carefully coordinated with specific conduct prohibitions, with clear prioritization.