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松下 外
松下 外


  • Counsel
  • Tokyo

With a background in engineering, Gai’s practice focuses on intellectual property, IT, AI, data, and other cutting-edge technology related matters, especially disputes both domestic and international.

Gai handles a wide variety of IP related disputes including IP infringement litigation and trials as well as non-contentious matters including drafting and reviewing IP related agreements. With an engineering background, Gai has particular expertise in patent related matters but is also adept at handling copyrights, trademarks and trade secrets. 

Gai also advises tech ventures and startups on cutting-edge technological matters involving AI, IoT and data including data privacy. Gai served as a member of the team that drafted the “Contract Guidelines on the Utilization of AI and Data,” Japan’s first comprehensive guidelines on AI and data related contracts published by the Japanese Government in June 2018. His strength in technology related matters is widely acknowledged by clients: “Gai Matsushita is particularly experienced in the technical field while having a deep knowledge of law, he is an excellent lawyer who leads his client in the right direction” (Legal 500 Asia Pacific 2020).

Gai is active in the field of international dispute resolution. Based on his experience working at leading firms in Singapore and New York, Gai has represented clients in several international commercial arbitration cases seated outside of Japan and in arbitration related domestic procedures including applications for provisional dispositions in Japan.

Awards & Rankings





New York University School of Law (LL.M. in International Business Regulation, Litigation and Arbitration)
The University of Tokyo (J.D.)
Tokyo Institute of Technology (B.Eng. in Computer Science)

Professional Experience

Lecturer, Japan Patent Attorneys Association, Training Program for Counsel on Proceedings Alleging Specific Infringement
Member, Ministry of Economy, Trade and Industry, Expert Committee for Drafting a “Data Linkage Model Contract”
Specialist Mediator Panel (Japan) Member, Singapore International Mediation Centre (SIMC)
APAC member, The Young SIAC (YSIAC) Council, Singapore International Arbitration Centre (SIAC)
Mentor, the Japan Patent Office, "IP Acceleration Program for Startups (IPAS)"
Member, Fisheries Agency, "Study Group on Preservation of High-Quality Breeds in the Fisheries Industry"
Member, the Japan Federation of Bar Associations (JFBA), "Committee on Intellectual Property Rights (Patent Project Team)"
Member, Ministry of Economy, Trade and Industry, “Study Group for the Promotion of Inter-company Data Provision for AI Human Resource Development”
Atsumi & Sakai
Working Group Committee Member, New Energy and Industrial Technology Development Organization (NEDO), the "Development of Infrastructures for Creating New Industrial Models Taking Advantage of IoT"
Member, SIAC Users Counseil, Singapore International Arbitration Centre (SIAC)
Member, Ministry of Economy, Trade and Industry, "Study Group on AI/Data Contracts Guidelines"
Visiting Scientist, RIKEN Center for Advanced Intelligence Project, "Privacy and Social System Team"
Innoventier LPC Tokyo Office
Hughes Hubbard & Reed LLP, New York
Allen & Gledhill LLP, Singapore
Kitahama Partners Tokyo Office