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Mori Hamada & Matsumoto

Work +81 3 6212 8330
Fax +81 3 6212 8230
Bangkok, Beijing, Fukuoka, Ho Chi Minh City, Osaka, Shanghai and 3 more

Atsushi Okada

Work +81 3 5220 1821
Mori Hamada & Matsumoto


Intellectual Property, IT, Litigation/Dispute Resolution


Admitted to practice in 2002 (Japan) and in 2008 (New York); with Weil, Gotshal & Manges LLP, Silicon Valley (2007-2008); Partner of Mori Hamada & Matsumoto (2012-present); Lecturer at Rikkyo University (2010-2011); Visiting Professor of Aoyama University (2011-present); Advisor for Damage from Counterfeit Products, Japan Institute for Promoting Invention and Innovation (2012-present); Lecturer for the Infringement Litigation Training Program for Patent Attorneys at the Japan Patent Attorneys Association (2015-present)


Japanese and English


Daini-Tokyo Bar Association; New York State Bar Association


Harvard Law School (LL.M., 2007), The University of Tokyo (LL.B., 2001)

Japan: Intellectual property

Intellectual property – Independent local firms

Within: Leading individuals

Atsushi Okada - Mori Hamada & Matsumoto

Within: Intellectual property – Independent local firms

Traditionally known for its focus on patents, Mori Hamada & Matsumoto also has significant expertise in trade mark matters. In complex, cross-border IP transactions the team takes advantage of the firm's full-service offering and five foreign branches in Beijing, Shanghai, Singapore, Bangkok and Yangon. Yutaka Miyoshi heads the team, which includes Yoshifumi Onodera, who is a key name for domestic and international disputes, and Atsushi Okada, who represented Hospira, a provider of injectable drugs and infusion technologies, in patent infringement litigation filed by Debiopharm International; in July 2017 the Intellectual Property High Court upheld an earlier decision by the Tokyo District Court to dismiss the plaintiff’s claim. Other clients include Pfizer Japan, Mitsuba and Shiseido.

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Legal Developments by:
Mori Hamada & Matsumoto

Legal Developments in Japan

Legal Developments and updates from the leading lawyers in each jurisdiction. To contribute, send an email request to
  • Taking control of a Japanese publicly listed company:

    Introductory notes for successfully completing an M&A
  • Yuasa and Hara Business Law News

    Contents of the Issue Law on liability for breach of contract Review on the amendment to the cabinet office order on Corporate Disclosure

    The Minister for Justice, Alan Shatter (“the Minister”), has published the Criminal Justice Bill 2011 (“the Bill”). The main purpose of the Bill is stated to be “…to amend the criminal law to improve certain procedural matters and strengthen Garda investigative powers. The intention is that such improvements will assist in reducing the delays associated with the investigation and prosecution of complex crime, in particular white collar crime.”
  • Japan: New legislative framework for Sukuk

    The new framework passed in May 2011 will provide a solid legal platform for issuing Sukuk Ijarah under Japanese law. NAOKI ISHIKAWA highlights key legal structures and tax treatment in respect of the anticipated Sukuk issuances in Japan.
  • Yakult Bottle Acquired Distinctiveness

    Do you know about Yakult's delicious lactic acid drink which is contained in a small bottle? Yakult's lactic acid drink (hereafter referred to as "Yakult drink") is the most famous lactic acid drink in Japan and today is also being sold in many countries around the world. When you are enjoying Yakult drink, please keep in mind the case mentioned below.
  • Tax: Japan: International Joint Ventures

    Tax on international joint ventures. Country Q&A (Japan).
  • Japan: Recent Developments in Practice and Law

    The successful closing of two Islamic fi nance transactions which was announced in July 2010 by Nomura Holdings have paved a concrete path for Japanese corporations to consider overseas Islamic fi nance markets for their fund raising activities. The fi rst transaction was in Asia for the issuance of Sukuk Ijarah and the second was in the Middle East for the establishment of a Commodity Murabahah facility (Nomura Deals).
  • Renewable energy takes off in Japan

    Like many other countries, Japan has decided to reform its renewable energy (RE) policy, to dramatically increase the use of renewable energy. The core policy mechanism is a feed-in tariff (FIT). This chapter summarises the contemplated Japanese FIT and its practical impact on existing and future investment in this sector, providing an overview of:
  • Licensing - 2010

    Q & A on Licensing in Japan 
  • Law on the Civil Jurisdiction of Japanese Courts over Foreign Countries, etc.

    The Law has been enacted to clarify the scope of application of the civil jurisdiction of Japanese courts over foreign countries, etc., and set exceptions to civil preocedings involving foreign countries, etc., based on the United Nations Convention on the Jurisdictional Immunities of States and their property (UN Convention on Immunities) (see Article 1).