A headshot of Masa Yamaguchi.

Masa Yamaguchi

Partner
Portland

Masa Yamaguchi is Co-Leader of the firm’s Japan practice and represents clients in a broad range of corporate matters, including contract, mergers and acquisitions, securities, corporate governance, and compliance issues.

Drawing on his language skills, work experience, and understanding of Japanese culture, a large part of Masa’s practice involves advising global corporations regarding cross-border transactional matters and disputes in the United States. He regularly acts as outside general counsel to Japanese clients, advising on various matters including formation, corporate governance, mergers and acquisitions, compliance, and divestures.

Masa has experience in multi-national antitrust criminal investigations and antitrust class actions. He is actively involved in the legal and business community. He currently serves as the chair of the Japan-America Society of Oregon (JASO) and is a member of Shokookai of Portland (Japanese Business Association of Portland).

Experience 

Representative Matters

  • Represented Hoosiers, a Japan-based real estate company, in its joint venture with Wilshire Capital
  • Advised Hoosiers on the JV agreement, service agreement, loan agreement and loan modification agreements for the development of the Canyons Apartments
  • Represented Tokai Carbon Co., Ltd. in its $310M acquisition of Sid Richardson Carbon, Ltd
  • Represented a Japanese restaurant chain's divestiture of assets to its joint venture partner
  • Represented a Japanese company in the divestiture of its equity interests in a developer of dietary supplements
  • Represented a Japanese regional bank's reorganization in the United States
  • Represented a Japanese shareholder in its dispute with another shareholder of a closely held U.S. corporation

Professional Highlights

Professional Activities

Oregon Bar Association, International Law Section, Past Chair

Oregon Minority Lawyers Association

Oregon State Bar, Business Law Section

Oregon Asian Pacific American Bar Association

Recognition & Accomplishments

The Best Lawyers in America, Corporate Law, 2025

Best Lawyers: Ones to Watch, Corporate, 2021

Thomson Reuters, "Oregon Rising Star," Antitrust Litigation, 2017; Mergers & Acquisitions, 2018-2019

Lewis & Clark Law School Small Business Legal Clinic, “Pro Bono Champion,” 2021

Speaking Engagements

“Doing Business in Oregon,” Tokyo Seminar, April 2013 and 2014

Pro Bono Experience

Masa frequently provides pro bono services for entity formation and contract drafting at Lewis & Clark Small Business Legal Clinic.

Board Memberships & Community Service

Japan-America Society of Oregon (JASO), Board Chair

Japan-America Society of Oregon (JASO), Board Chair; Business Affairs Committee

Portland Shokookai (Japanese Business Association of Portland), Welfare Committee

Credentials 

Education

Lewis & Clark Law School (J.D. 2008)
Business Law Certificate
Recipient of Research Fellowship Program
Minority Law Student Association

Portland Community College (Paralegal Certificate Program 2004)

Dokkyo University (B.A., French, 1996)

Languages

Japanese - Native

Admissions

Oregon