Ryutaro Oka

Ryutaro Oka

Baker & McKenzie (Gaikokuho Joint Enterprise)


Ryutaro Oka has significant experience in the finance, trade, energy and manufacturing industries, where he has developed and maintained good client relationships. He regularly advises on complex international tax issues, working extensively with colleagues in the US, UK, Netherlands, China, Singapore and Thailand. Mr. Oka is a frequent speaker on international tax issues, having been invited to speak on international taxation and cross-border private equity investments at events sponsored by the Association of Taxation Analysis, among others. Prior to joining the Firm in 2006, Mr. Oka was a tax director at Deloitte Touche Tohmatsu's Tokyo office, where he advised on international tax issues. Mr. Oka is fluent in English.

Practice Focus

Mr. Oka's main practice focus is cross-border M&A taxation. In this connection, he routinely advises on overseas holding company schemes, including the formulation of worldwide tax-efficient acquisition structures, tax due diligence issues, as well as other international taxation matters. He advises as well on the structure of international PE funds and hedge funds. Mr. Oka also advises large family owned companies, and provides succession planning strategies for the founding owners of those companies. Additionally, Mr. Oka handles general taxation matters, including organizational restructuring, and advises regarding Japan's consolidated taxation system.

Representative Legal Matters

  • Advised a number of Japanese multinational corporations on improving tax efficiency on a global basis.
  • Advised a major precision equipment manufacturer regarding a squeeze out structure resulting from a cash-out merger.
  • Advised on the structuring of the sale of a business of a major foreign-affiliated communications company.
  • Advised on structuring the integration of listed companies by way of cross-border triangular merger.


  • Licensed Tax Attorney (Zeirishi)~Japan (1999)


  • English
  • Japanese

Co-author, “Legal and tax practices on conducting business in Asia - from business start-up to expansion and withdrawal,” Chuokeizai-sha, August 2011, Language: Japanese

Co-author, M&A Handbook on Conducting Business Practically, Chuokeizai-sha, June 2010, Language: Japanese

Co-author, Cross-Border M&A Practice, Chuokeizai-sha, July 2008