Masa Yamaguchi

Shareholder | Portland | 503.778.2174 |

Areas of Practice

Masa Yamaguchi has M&A and other corporate practice with focus on Japan. He regularly works as outside general counsel for Japanese companies of various sizes. He is also experienced in international litigations, including criminal antitrust investigations and antitrust class actions.

Professional Experience

  • PacifiCorp — General Counsel’s Office, Legal Intern (2006-2008)
  • Lane Powell PC, Paralegal (2000-2004)
  • Okachi, Inc, Commodity Broker (1996-1998)

Admitted to Practice

  • Oregon


  • Lewis & Clark School of Law (J.D., 2008)
    • Business Law Certificate
    • Recipient of Research Fellowship Program
    • Minority Law Student Association, Member
  • Portland Community College (Paralegal Certificate Program, 2004)
  • Dokkyo University (B.A., French, 1996)

Practice Group and Specialty Team Memberships

  • Mergers and Acquisitions
  • Electronic Discovery, Technology and Strategy
  • Intellectual Property and Technology
  • International Business
  • Antitrust and Trade Regulation
  • Electronic Discovery Committee

Speaking Engagements

  • Doing Business in Oregon (April 18, 2014)
  • Doing Business in Oregon (April 19, 2013)

Awards and Honors

  • Named as an “Oregon Rising Star,” Super Lawyers® magazine, Antitrust Litigation (2017)

Professional and Community Activities

  • Vice Chair, Japan-America Society of Oregon (JASO)
  • Executive Committee, Oregon Bar Association, International Law Section
  • Executive Committee, Oregon Bar Association, Antitrust and Trade Regulation Section
  • Member, Oregon Minority Lawyers Association
  • Member, Oregon State Bar, Business Law Section
  • Member, Oregon Asian Pacific American Bar Association
  • Member, American Bar Association, Antitrust Section
  • Member, Multnomah Bar Association
  • Member, Shokookai (Japanese Business Alliance)


  • Japanese