Hideo Oka | Japan–Mongolia Legal Expert | Taisho Law Firm
Hideo Oka, Attorney-at-Law
Founder of Taisho Law Office.
Provides legal services in both Japan and Mongolia, handling a wide range of matters for corporate and individual clients, with a focus on domestic cases and Mongolia-related legal practice.
Drawing on experience in international judicial cooperation, including institutional support at the Supreme Court of Mongolia, offers practical and realistic solutions based on both local legal systems and on-the-ground practice.
Also actively handles domestic matters in Japan, including civil, family, and corporate cases. Services cover areas such as inheritance, divorce, traffic accidents, and employment termination.
Date of Birth / Place of Origin:
Born in 1972, Kobe City, Hyogo, Japan
Education:
J.D. (Professional Degree), Graduate School of Law, Kyoto University
LL.B., Faculty of Law, Kwansei Gakuin University
Yumenodai High School, Hyogo Prefecture
Qualifications:
Attorney-at-Law (Osaka Bar Association, Registration No. 36958)
Registered Foreign Lawyer in Mongolia (Ministry of Justice of Mongolia, Registration No. 18)
Arbitrator, Mongolian International Arbitration Center
Maritime Counselor
Passed the National Public Service Examination (First Class, Legal)
Passed the Court Clerk Examination (First Class)
Professional Appointments:
Contracted Attorney for Japanese Business Support, Embassy of Japan in Mongolia
Member, International Exchange Committee (Head of Mongolia Project Team), Japan Federation of Bar Associations (JFBA)
Executive Member, International Legal Services Promotion Headquarters, JFBA
Attorney for SME Overseas Expansion Support, JFBA
Member, International Committee, Osaka Bar Association
Former Chief Advisor, JICA Project for Strengthening Mediation System, Supreme Court of Mongolia
Former Drafting Committee Member, Mediation Law, Office of the President of Mongolia
Former Drafting Committee Member, Mediation Rules, Supreme Court of Mongolia
Former Court Clerk and Judicial Administrative Officer (Takamatsu High Court, Tokushima District Court, etc.)
Director, Mongolia Labor and Social Protection Service Center
Auditor, Kansai Mongolia Friendship Association
Academic and Other Activities:
Former Part-time Lecturer (Constitutional Law, Labor Law), Kobe Gakuin University
Part-time Lecturer (Civil Law), Mukogawa Women’s University
Part-time Lecturer (Constitutional Law), Kinki University Kyushu Junior College (Distance Education Division)
Attended the State Banquet hosted by the President of Mongolia in honor of Their Majesties the Emperor and Empress of Japan (2025)
Major Awards and Honors:
Practice Areas:
Mongolia legal services (investment, dispute resolution, criminal and civil matters)
Cross-border disputes (Japan–Mongolia)
International arbitration and mediation
Corporate legal services (contracts, advisory)
Legal support for Japanese companies entering or operating in Mongolia.
Publications
Title: You Should Be the One to Work Hard
— 2,045 Days of Legal System Development Support at the Supreme Court of Mongolia
Author: Hideo Oka
Publisher: Judicial Association
Format: Shinsho (paperback), 264 pages
Price: ¥900 (excluding tax)
Publication Date: September 2016
ISBN978-4-906929-57-3
Arbitration and ADR Forum Vol. 6
“Court-Annexed Mediation in Mongolia” (contributed by Hideo Oka)
Edited by the Japan Association of Arbitrators
Format: Book, 136 pages
Publisher: Shinzan-sha (January 30, 2019)
ISBN-10: 4797269030
ISBN-13: 978-4797269031
Release Date: January 31, 2019
Price: ¥2,500 (excluding tax)
“International Activities by Lawyers and Their Future Prospects” (co-authored)
Edited by the Japan Federation of Bar Associations Research Foundation
Publisher: Shojihomu (August 13, 2025)
Format: Paperback, 320 pages
ISBN-10: 4785731796
ISBN-13: 978-4785731793
Release Date: August 13, 2025
Price: ¥3,600 (excluding tax)
Articles, Media Appearances, and Other Activities
Numerous other publications, lectures, and presentations.
Appeared on BTV Cable Television, “Mongolia Today” (broadcast March 13–19, 2019).
Message
I am a Japan–Mongolia legal practitioner focusing on cross-border disputes, arbitration, and Mongolia-related legal matters.
My experience includes serving as a legal advisor to the Supreme Court of Mongolia and contributing to the development of its mediation system. Based on this background, I provide practical legal solutions that reflect both the formal legal framework and the realities of local practice.
I regularly handle international cases involving Japanese and Mongolian parties, including investment disputes, corporate matters, civil litigation, and criminal cases. I work closely with a trusted network of lawyers, courts, and institutions in both countries to ensure effective and reliable outcomes.
My role is not limited to legal analysis. I provide strategic, realistic, and execution-oriented advice to protect my clients’ interests in complex cross-border situations.
Please contact us for Mongolia-related legal matters and cross-border disputes.
Mongolia Legal Expert | Lectures, Publications and Government Training
Hideo Oka is a Japan–Mongolia legal expert with extensive experience in cross-border disputes, arbitration, and legal system development.
He has delivered over 240 lectures and presentations and conducted more than 30 government training programs in Japan and Mongolia.
His work includes legal system development at the Supreme Court of Mongolia, training of judges and mediators, and advisory services for Japanese companies operating in Mongolia.
Mongolia Legal Services and International Practice
- Legal support for Japanese companies entering or operating in Mongolia
- Cross-border disputes between Japan and Mongolia
- International arbitration and mediation
- Investment, corporate, civil, and criminal matters in Mongolia
Legal System Development in Mongolia
Hideo Oka has been directly involved in the development of Mongolia’s mediation system.
Key activities include:
- Legal advisor to the Supreme Court of Mongolia
- Drafting and implementation support for mediation laws and regulations
- Nationwide training programs for judges, lawyers, and court officials
- Public seminars and institutional capacity-building across Mongolia
Publications and Research
Selected publications include:
- Annual Reports for the JICA Mediation Project (2010–2015)
- “International Commercial Arbitration in Mongolia” (JCA Journal)
- “Mediation System in Mongolia” (JCA Journal)
- Contribution to Energy Investment Risk Assessment 2018 (EIRA2018)
- “Research on Mediation in Mongolia” (lead researcher, 2024)
- “International Activities by Lawyers and Their Future Prospects” (co-authored)
Government and Institutional Training
Conducted legal training for:
- Osaka Prefecture (Administrative Law Training Programs)
- Kobe City and other local governments
- Ministry of Finance (Customs Training Institute)
- Japan Legal Support Center (Houterasu)
Topics include administrative law, constitutional law, and legal risk management in public administration.
Lectures and Academic Activities
- Lectures at universities and law schools in Japan and Mongolia
- International seminars on arbitration, mediation, and legal development
- Training programs for legal professionals and government officials
Why This Matters
Few lawyers combine:
- Practical legal experience in Japan and Mongolia
- Direct involvement in Supreme Court-level legal system development
- Extensive training experience for government and legal professionals
This combination enables practical, execution-oriented legal solutions in complex cross-border matters.
Contact
Please contact us for Mongolia-related legal matters, arbitration, and cross-border disputes between Japan and Mongolia.