Hakuhodo DY Holdings Research Paper Accepted by Major Law Journal 'International Data Privacy Law'

Hakuhodo DY Holdings Inc. (Minato-ku, Tokyo; Masahiro Nishiyama, President & CEO) is pleased to announce that a paper by Seiichi Inatani, Senior Researcher at its Marketing Technology Center (MTC), has been accepted for publication in International Data Privacy Law (IDPL), a leading journal in the field of law published by Oxford University Press.

### Research Background The Hakuhodo DY Group operates based on 'Sei-katsu-sha Insight,' an approach that understands people not merely as 'consumers' or 'data' points, but as holistic individuals with their own lives. Since 2013, the MTC has conducted legal, ethical, and social research aimed at ensuring appropriate privacy considerations and understanding global data protection laws to pursue this insight within marketing, advertising, and AI technologies.

Following the implementation of the EU's General Data Protection Regulation (GDPR), interest in data protection has surged in Japan, leading to active debates on the fundamental principles of the Personal Information Protection Law. Rather than simply following these discussions, the MTC has actively participated in academic debates, leveraging its experience in handling consumer data. Following a previous paper published in IDPL in October 2025 regarding the origin of the 'personal information controller' concept in Japan, this new paper focuses on 'regulatory architectures'—a factor that fundamentally dictates the nature of data protection laws—and explores how structural differences affect actual data utilization practices.

### Journal Overview IDPL is a high-impact journal, ranking 53rd out of 434 law journals in Clarivate’s Journal Citation Report (2024 Impact Factor: 1.9) and 95th out of 1,089 law journals in the Scopus SJR rankings (2024 SJR: 0.850). It is recognized as a major publication not only in privacy law but across the entire legal field.

### Paper Summary - **Title:** Operator-first versus operation-first: Regulatory architectures in data protection law and the Meta Platforms judgment - **Journal:** International Data Privacy Law (Oxford University Press) - **Author:** Seiichi Inatani (Hakuhodo DY Holdings Inc. / Information Law Institute) - **DOI:** 10.1093/idpl/ipag006

The paper proposes a new analytical framework for data protection law by demonstrating that Japan’s law is built on an 'operator-first' structure (regulating based on the entity), while the GDPR follows an 'operation-first' structure (regulating based on the processing of personal data). Through an analysis of European Court of Justice case law, it highlights the respective merits and demerits of these regulatory architectures.

### Future Outlook Discussions regarding the future of data protection legislation are expected to remain active both domestically and internationally. The MTC hopes that the analytical framework and trade-offs proposed in this paper will contribute to these discussions. The center will continue its research and development to contribute to the proper development and social implementation of marketing technology.