YU MARUYAMA
Yu Maruyama specializes in intellectual property litigation, including patent infringement suits (with expertise in standard essential patents), trademark disputes, unfair competition cases, and invalidation proceedings before the Japan Patent Office. He has extensive experience in developing and implementing anti-counterfeiting strategies. Mr. Maruyama also advises multinational companies on employment matters, including performance-based terminations, disciplinary actions, and dispute resolution. Additionally, he represents major airlines in complex aircraft financing transactions.
Profession
Attorney at Law
Patent Attorney
Admissions
Attorney at Law, Japan (2017)
Patent Attorney, Japan (2026)
Membership
Dai-Ichi Tokyo Bar Association
Japan Patent Attorneys Association
Dai-Ichi Tokyo Bar Association Institute of General Legal Studies, Intellectual Property Law Study Group
Tokyo Bar Association Legal Research Division, Intellectual Property Law Section
International Association for the Protection of Intellectual Property of Japan (AIPPI Japan)
IP Lawyers Network Japan
Professional Experience
2026 – Present – Sonderhoff & Einsel Law Office
2021 – 2025 – Sonderhoff & Einsel Law and Patent Office
2018 – 2021 – Chuo Sogo Law Office, P.C.
Education
2016 – University of Tokyo, School of Law (J.D.)
2014 – Keio University (LL.B.)
Publications
"Intellectual Property Law Annual Report 2025-2026" (Trends in Various Countries in 2025 "II. Intellectual Property Developments in Europe" "1. Patents") (Nippon Hyoronsha, Co-author), February 2026
"Introduction to Intellectual Property Legal Practice Q&A - From Basic Knowledge to Contracts, Applications, and Infringement Response" (Minjiho Kenkyukai, Co-author), January 2026
“Business Operators’ Response to the Amended Whistleblower Protection Act as Clarified in Detail by Guidelines and Guidelines Commentary” S&E Newsletter, March 2022
“Is Your Company Prepared for the Implementation of the Personal Information Protection Act on April 1, 2022?” S&E Newsletter, February 2022
“Whistleblower System Theory and Practice” (Shoji Homu, Co-author) January 2021
“Life and Money Vol. 6 – Things You Need to Know! Civil Code Amendment Q&A” (Business Kyoiku Shuppansha, Co-author) September 2019
“Current Status of Board Evaluation (2018 edition) – Analysis of Domestic and Overseas Disclosure Cases” (Shoji Homu, Co-author) October 2018
“Case Studies of Corporate Misconduct: Actual Cases and Judicial Precedents” (Shoji Homu, Co-author) October 2018
“Tax & Law – Business Transfers, Company Splits, Stock Transfers, Mergers, Rehabilitation Liquidation” (Dai-Ichi Hoki, Co-author)
“Corporate Handbook of Executive Duties and Treatment” (Dai-Ichi Hoki, Co-author)
Lectures
Languages
Japanese, English
