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Mitsuru Tadatsu focuses his practice on commercial litigation, commercial arbitrations, employment litigation, and enforcements involving not only domestic companies, but also multinational conglomerates. He has also been engaged in employment law, general corporate, mergers and acquisitions, and intellectual property matters.

Mitsuru previously worked out of the firm's Tokyo office. Prior to joining Greenberg Traurig, he worked at a prominent Japanese law firm where he was engaged in general corporate matters, corporate litigation, labor disputes, intellectual property disputes, and insolvency matters. He also has experience working as an in-house corporate attorney on secondment at a major international consulting firm.



  • Represented a Japanese consulting firm in a breach of contract lawsuit brought by a former customer related to system integration.
  • Represented a Japanese subsidiary of a U.S. company in an employment lawsuit related to the dismissal of an employee.
  • Represented a subsidiary of a U.S. multinational technology company in a patent infringement litigation seeking an injunction and damages for the sale of an artificial intelligence product.
  • Represented a Japanese subsidiary of a global company and its senior management employees in a harassment lawsuit brought by a former employee.
  • Assisted a Japanese electric power company in defeating most of the claims made by a foreign mining conglomerate in an arbitration that was heard before the International Chamber of Commerce (ICC) and seated in Tokyo.
  • Assisted a client in obtaining the dismissal of all claims in Japan Commercial Arbitration Association (JCAA) proceedings between alleged joint venture partners in the development of a mega-solar power plant in Japan.
  • Represented a Belgian financial institution on an enforcement of a notarial deed in Japan.
  • Assisted a local litigation attorney in New York with the submission of an expert opinion regarding Japanese civil law and civil procedure in U.S. litigation.
  • Assisted a client in discovery procedures in U.S. litigation, including reviewing Japanese-language emails and documents.
  • Conducted labor due diligence related to long working hours and labor law compliance issues in a Japanese subsidiary of a European multinational.
  • Assisted a Japanese subsidiary of a U.S. company with its internal investigation of an injury accident in the workplace, provided an opinion regarding recommended future actions, and made recommendations regarding the legal risks arising from the accident.
  • Implemented anti-harassment measures for a Japanese subsidiary of a U.S. health care company.
  • Conducted due diligence for M&A related to a Japanese technology company (buyer side).
  • Reviewed and advised on M&A contracts for a Japanese employment placement company (seller side).
  • Provided corporate law advice on the issued shares of a Japanese subsidiary in connection with the restructuring of a UK holding company.
  • Advised a European consulting firm on a general corporate matter under Japanese laws.
  • Assisted with the reorganization of a Japanese subsidiary of a U.S. chemical materials company (conversion to a limited liability company under the Companies Act).
  • Reviewed and advised a Japanese apparel manufacturing company on trademark and design license agreements with a famous U.S. fashion brand.

Recognition & Leadership

  • Listed, The Best Lawyers in Japan, Ones to Watch: Intellectual Property Law (Non-Patent), 2023-2024
  • Member, Daiichi Tokyo Bar Association


  • Master of Laws, Certificate in International Arbitration and Dispute Resolution, Georgetown University Law Center, 2022
  • LL.B., Hitotsubashi University, 2010
  • Japan
  • New York
Admitted to practice in Japan and New York. Not admitted in the District of Columbia.
  • Japanese
  • English