Partner

Masayuki Atsumi

Bar Admissions

admitted in Japan, 2009
admitted in New York, 2016
admitted in England & Wales, 2017
Daini Tokyo Bar Association

Contact Information

TEL +81-3-6270-3516
FAX +81-3-6270-3501

Languages

Japanese, English

Offices/Locations

Tokyo Head Office

Background

Kobe University School of Law (J.D., 2006)
Japan Fair Trade Commission (2006 - 2008)
Mori Hamada & Matsumoto (2009 - 2017)
University of Chicago Law School (LL.M., 2015)
Covington & Burling LLP (on secondment, 2015)
U.S. Federal Trade Commission (on secondment, 2016)
General Manager for Compliance, LIXIL Corporation (2017 - 2018)
Outside Director, Audit and Supervisory Committee Member, ARCLANDS CORPORATION (2022 - present)
Audit & Supervisory Board Member, TOKAI Holdings Corporation (2023 - present)
Auditor, Electric Power Reserve Exchange (2024 - present)
Lecturer at the Kobe University Graduate School of Law (2024 - 2025)

Practice Areas

Corporate Governance

Corporate Governance

Competition Laws

Competition Laws
Subcontract Act
False Advertisement and Unjustifiable Premiums Act

Crisis Management

Compliance
Fraud Investigation
Response to scandals

Information Security

Information Security

Litigation and Disputes

Corporate Law Disputes
International Disputes
Alternative Dispute Resolution (ADR)

Government Relations

Government Relations

International Practice and Trade Law

International Practice
International Trade Law

Publications

2025.01.11	GIR Know how – Anti-money Laundering 2024: Japan Articles
2024.11.22	Chambers Global Practice Guides – Anti-Corruption Japan 2025: Trends and Developments Articles
2024.10.10	The Legal 500 - Merger Control Comparative Guide: Japan (9th Edition) Articles
2024.09.06	Lexology Panoramic - Complex Commercial Litigation 2025: Japan Chapter Articles
2024.05.29	The Importance of an Effective Antimonopoly Act Compliance Program Articles
2024.01.18	Reinforcing Japanese anti-bribery regulation against foreign officials Articles
2023.12.07	Chambers Global Practice Guides – Anti-Corruption Japan 2024: Trends and Developments Articles
2023.12.04	GIR Know how – Anti-money Laundering 2023: Japan Articles
2023.11.02	International Comparative Legal Guide - Cartels & Leniency 2024: Japan Articles
2023.10.10	The Legal 500 - Merger Control Comparative Guide: Japan (8th Edition) Articles
2023.09.26	Lexology Getting the Deal Through - Complex Commercial Litigation 2024: Japan Chapter Articles
2023.09.04	Direct Marketing in Japan: Overview Articles
2023.07.07	Mitigating Risks of Corporate Scandals by the Effective Whistleblowing System Articles
2022.12.16	GIR Know how – Anti-money Laundering 2022: Japan Articles
2022.11.04	International Comparative Legal Guide - Cartels & Leniency 2023: Japan Articles
2022.10.06	The Legal 500: Merger Control Comparative Guide - Japan Articles
2022.09.13	Lexology Getting the Deal Through - Competition in Digital Markets 2023: Japan Chapter Articles
2022.08.10	Lexology Getting the Deal Through - Government Investigations 2023: Japan Chapter Articles
2021.11.02	International Comparative Legal Guide - Cartels & Leniency 2022: Japan Articles
2021.09.23	Lexology Getting the Deal Through - Competition in Digital Markets 2022: Japan Chapter Articles
2021.08.11	Lexology Getting the Deal Through - Government Investigations 2022: Japan Chapter Articles
2021.06.15	Japan introduced very limited attorney-client privilege for antitrust contexts – what in-house counsel should know – Articles
2020.11.05	Lexology Getting the Deal Through - Digital Competition 2021: Japan Chapter Articles
2020.08.09	Lexology Getting the Deal Through - Government Investigations 2021: Japan Chapter Articles
2020.06.22	Merger Filing Guide: Japan Chapter Other

Seminars

2025.02.11	The Fundamentals of East Asia Merger Control (China, Japan & South Korea) External Seminars
2024.11.13	ICN Merger Workshop 2024 External Seminars
2023.11.28	Trends in Global Enforcement and Expectations for Compliance Programs External Seminars
2023.10.09	Competition Policy in the Digital Age: Priorities and Challenges for APAC Economies External Seminars
2023.07.21	ICC Conference on Antitrust Enforcement Between Globalisation and Deglobalisation External Seminars
2023.03.07	ICN Unilateral Conduct Workshop External Seminars
2022.03.31	Platforms and the sharing of sensitive information External Seminars
2021.09.24	Competition Laws in India and Recent Developments External Seminars
2020.03.06	Competition Laws in India and Recent Developments External Seminars
2019.11.19	Competition Laws in India and Recent Developments External Seminars

News

2025.04.17	The Best Lawyers - 2026 edition Awards & Rankings
2025.01.16	The Legal 500 Asia Pacific 2025 Awards & Rankings
2024.08.07	Masayuki Atsumi chosen in Who's Who Legal: Competition 2024 Awards & Rankings
2024.04.18	The Best Lawyers - 2025 edition Awards & Rankings
2024.01.17	The Legal 500 Asia Pacific 2024 Awards & Rankings
2023.12.01	Masayuki Atsumi commented on "DESTINATION EUROPE" Media
2023.10.02	Masayuki Atsumi chosen in Who's Who Legal: Japan 2023 Awards & Rankings
2023.09.05	Masayuki Atsumi chosen in Who's Who Legal: Competition 2023 Awards & Rankings
2023.06.20	Masayuki Atsumi commented on "Japan's law firms look overseas as competition heats up at home" Media
2023.06.05	Legal Business - Deals Yearbook 2023: Sponsored breifing: Japan - Miura & Partners Media
2023.04.20	The Best Lawyers - 2024 edition Awards & Rankings
2023.04.01	Masayuki Atsumi and Yuhei Sakao commented on "RISING FROM THE EAST" Media
2023.03.07	JAPAN’S MIURA ANNOUNCES MAJOR GLOBAL EXPANSION Media
2023.03.06	Miura & Partners Announces Opening of San Francisco, Jakarta, and London Offices in April Notice
2023.01.11	The Legal 500 Asia Pacific 2023 Awards & Rankings
2022.04.14	The Best Lawyers - 2023 edition Awards & Rankings
2021.04.20	Masayuki Atsumi commented on "Japan's JFTC dawn raids on power utilities have potential impact on grid regulations– analysis" Media
2021.04.15	The Best Lawyers - 2022 edition Awards & Rankings
2021.01.14	Masayuki Atsumi commented on "Japan’s amended AMA enhances cartel investigations but draws lukewarm response of companies: lawyers" Media
2021.01.11	Masayuki Atsumi commented on "Google/Fitbit: EC commitments help clear Japanese M&A approval: lawyers" published by PaRR Media
2020.10.14	Masayuki Atsumi named in “ALB Asia 40 Under 40” Awards & Rankings
2020.04.10	The Best Lawyers - 2021 edition Awards & Rankings
2019.10.04	Masayuki Atsumi appointed as Lecturer at the Kobe University Law School Notice