While disclosure of individual clinical study reports (CSRs) is becoming common globally, this is not yet the case in Japan, where the national health authority does not require CSRs to be made publicly available. As CSRs of Japanese studies might be used for marketing applications in other countries and regions, Japanese pharmaceutical companies that would like to expand their market internationally need to prepare CSRs that can be used for global applications and disclosure. In this article, we introduce the current situation in Japan regarding disclosure of clinical study data.