MAXWIN LAW FIRM > Member

Japanese Attorneys

Masumura Noriaki

Masumura Noriaki

Partner (Attorney at Law)

As an attorney, I have gained broad experience across a wide range of matters, including M&A, financial regulatory matters, corporate restructuring, divorce, and inheritance.
In recent years, my practice has focused primarily on shareholder disputes, commercial disputes, and intellectual property matters. I also handle matters in other areas whenever possible.

Professional Membership

Dai-Ichi Tokyo Bar Association

Career

After graduating from the Department of Law, Faculty of Law, Keio University, I worked in legal positions at a manufacturing company listed on the First Section of the Tokyo Stock Exchange and at a foreign financial institution.

After completing the 60th Legal Training and Research Institute program, I was admitted to the bar in 2007.

I subsequently practiced at a law firm specializing primarily in corporate legal matters and at a major law firm in Tokyo. In April 2022, I established my own law office.

In June 2025, I established MAXWIN Law Office as a legal professional corporation, where I continue to practice today.

Publications

  • “Comprehensive Review of Potential Conflicts Among Financial Regulations”
    Financial Compliance, December 2007 (co-author)
  • “Legal Advice for Supporting the Overseas Expansion of Small and Medium-Sized Enterprises”
    Keizai Horei Kenkyukai, December 2013 (co-author)
  • “Q&A: From Tax Audits to Tax Litigation”
    Zeimu Kenkyukai Publishing, June 2014 (co-author)
  • “Tax and Legal Issues Concerning Virtual Currency”
    Weekly Tax Communication, February 26, 2018 and October 8, 2018

Lectures and Seminars

April, July, and October 2015
“Mainichi Shimbun Seminar: Understanding Inheritance and Gifts”
July and October 2015
“Legal and Tax Knowledge of SPCs for Real Estate Professionals”
April 2017
“Legal and Tax Issues Concerning Virtual Currency”
Masumura Eiko

Masumura Eiko

Attorney at Law

Mainly handles various types of litigation.

Professional Membership

Dai-Ichi Tokyo Bar Association

Career

After graduating from Chuo University Law School, completed the Legal Training and Research Institute (65th class) and was admitted to the bar in 2024.

Chinese Lawyers

Ma Xin

Ma Xin

Chinese Lawyer (PRC-qualified)

With approximately 20 years of experience at a Chinese law firm, the legal department of a Japanese company, and a Japanese law firm, Ma Xin has handled China-related legal matters, corporate law, and cross-border matters between Japan and China. The practice covers a wide range of work, including Chinese companies entering Japan, Japanese companies doing business in China, M&A, contract negotiation, intellectual property, licensing, and dispute response.
Extensive experience in debt collection in Japan on behalf of Chinese companies. Working with Japanese attorneys, has handled many matters ranging from several million yen to several billion yen, seeing each through to resolution, from formulating a collection strategy suited to the case to negotiation, litigation, and other legal proceedings.
Particularly strong in the gaming and internet sectors. With experience managing game businesses, including the operation of the popular smartphone game Hōchi Shōjo (放置少女～百花繚乱の萌姫たち～), supports clients on game development and operation, licensing, intellectual property, advertising and labeling, personal data protection, and platform regulation from both legal and business-management perspectives.
Also led the planning and launch of “JPDD,” a platform that supports everything from corporate information gathering and analysis to AI-powered due diligence.
In the energy sector, has been involved in numerous projects, including battery storage, grid-scale storage facilities, and extra-high-voltage projects, handling business structuring, contract negotiation, legal due diligence, and research into related laws, regulations, and permits.

Career

After graduating from Peking University Law School, worked at Guantao Law Firm in Beijing and qualified as a PRC lawyer in 2009.
After completing the master’s program at the Graduate School of International Corporate Strategy, Hitotsubashi University, worked in the Legal Department of Fujitsu Limited and at Verybest Law Firm, and joined MAXWIN Law Office (Bengoshi Hojin) in 2026.

Languages

Chinese, Japanese, English

Guo Junyang

Guo Junyang

Chinese Lawyer (PRC-qualified) / Registered Foreign Lawyer (Gaikokuho Jimu Bengoshi), Japan

For more than nine years, has handled cross-border investment and Japan–China commercial transactions, including Chinese companies entering Japan, investment in China by Japanese and Western companies, M&A, joint venture (JV) formation, corporate governance, compliance, and contract negotiation.
A particular strength is supporting Chinese companies entering Japan, with many investment matters in AI, data centers, robotics, and entertainment. Provides end-to-end support, from investment structuring and legal due diligence to contract drafting and negotiation, company establishment in Japan, licensing and permits, and coordination with local professionals.
Experience as a head of corporate legal and as a law firm partner includes building corporate legal functions, contract management, commercial dispute response, and managing lawyer teams. Goes beyond legal risk analysis to deliver practical legal services that take business and management perspectives into account.

Career

After graduating from the Law School of Zhejiang University, worked at a Shanghai law firm focusing on investments in China by Japanese companies, and qualified as a PRC lawyer in 2017.
Subsequently served as head of legal at a technology company and as a law firm partner, working in corporate law, cross-border investment, and support for Chinese companies entering Japan.
Studied at Keio University Graduate School of Law (Global Legal Practice) in 2025. Began practice in Tokyo in 2026 as a Registered Foreign Lawyer in Japan.

Languages

Chinese, Japanese, English

Certified Tax Accountant

Namiki Junpei

[Namiki Junpei Tax Accountant Office]

Namiki Junpei

Certified Tax Accountant, Administrative Scrivener, Tax Litigation Assistant

Since opening Namiki Junpei Tax Accountant Office, has handled tax practice for individuals and corporations as well as asset-related taxation such as business succession and inheritance tax.
In addition to domestic Japanese taxation, strengths include tax consulting for overseas companies entering Japan, start-up support for Japanese entities, and structuring of investment vehicles.
Also able to offer tax optimization across corporate and individual levels and comprehensive proposals with inheritance and business succession in mind.

Career

Graduated from the Department of Business Administration, Faculty of Economics, Meiji Gakuin University, and served as an instructor for the tax accountant course at Ohara.
Subsequently worked at Melfis Co., Ltd., a support company for accounting and finance operations of the Mitsubishi Electric Group, in management analysis, accounting, tax, and labor-related consulting and seminar work.
Joined Verybest Tax Accountant Office in 2016, handling business succession, civil trust matters, and asset-related taxation including inheritance tax.

August 2019
Representative, Namiki Junpei Tax Accountant Office
August 2019
Representative, Impuest Co., Ltd.
September 2021
Representative, Impuest Administrative Scrivener Corporation

Judicial Scrivener

Otsu Masa

[Beis Judicial Scrivener & Administrative Scrivener Office]

Otsu Masa

Judicial Scrivener, Administrative Scrivener

Handles a wide range of matters, including company establishment and various registrations and other legal affairs, consultations on inheritance, wills, voluntary guardianship, and post-death administrative mandates, and real estate registration.
Also handles administrative scrivener work such as permit and license applications, with a commitment to approachable and reassuring support.

Professional Membership

Tokyo Judicial Scriveners Association (Registration No. 7295)
Certified Member for Summary Court Litigation Representation (Certification No. 1501157)
Tokyo Administrative Scriveners Association (Registration No. 19080027)

Career

1998
Graduated from Hattori Nutrition College
2014
Passed the Judicial Scrivener and Administrative Scrivener examinations

Certified Social Insurance and Labor Consultant

Iwama Yasuyuki

[A&I Social Insurance and Labor Consultant Corporation]

Iwama Yasuyuki

Specified Certified Social Insurance and Labor Consultant

Flexibly responds to a wide range of corporate needs, including consulting on HR and labor management, occupational safety and health, and labor and social insurance laws, administrative procedures for various social insurance schemes, and payroll processing.

Career

Born 1967
1990
After graduating from university, joined the HR and general affairs department of a private company
2006
Opened Iwama Social Insurance and Labor Consultant Office
2017
Established A&I Social Insurance and Labor Consultant Corporation
Former director
of the Tokyo Social Insurance and Labor Consultants Association
Former head
of its Toshima Branch