Ryutaro Nakayama is the Managing Partner of Nishimura & Asahi.


He specializes in General Corporate and M&A, and has rendered a broad-range of M&A-related advice to clients, including on Japanese corporate law, securities law, merger control, tax law and on regulations specific to various industries.


He is also a leading competition law lawyer. He has established a unique practice with interconnections between his abundant experience in M&A and corporate practice and his merger regulation expertise. He has successfully obtained clearance from the relevant competition authority even where the resulting combined market share exceeded 50% in the relevant markets.


He has also handled cross border cartel cases for Japanese clients by coordinating with law firms in various jurisdictions.


He has been selected as a leading lawyer in the Corporate/M&A and/or competition law fields by various publications such as Chambers Global, Chambers Asia-Pacific, and The Nikkei’s “Most Successful Lawyers” annual rankings.

Recent activities


Chambers Global 2022: Top rankings for Nishimura & Asahi



Chambers Asia-Pacific 2022: Top rankings for Nishimura & Asahi



asialaw Awards 2021



New York University School of Law (LL.M.)
University of Tokyo Graduate Schools for Law and Politics (LL.M.)
The University of Tokyo (LL.B.)

Professional experience

2021 -
Managing Partner
2020 -
Professor from Practice, The Business Law Department of Hitotsubashi University Graduate School of Law
2008 - 2009
Lecturer, Seikei University Law School
2007 - 2019
Lecturer, Chuo Law School
2004 - 2005
Weil, Gotshal & Manges LLP, New York

Major Cases


Sponsors led by J-Will Partners Co., Ltd. - Investment in Nichi-Iko Pharmaceutical Co., Ltd.


Idemitsu Kosan Co., Ltd. - Acquisition of TOA Oil Co., Ltd. through a tender offer


Honda Motor Co., Ltd. - Joint venture with LG Energy Solution for EV battery production in the U.S.


Medipal Holdings Corporation: Agreement to acquire Toshichi Inc.


Idemitsu Kosan Co., Ltd. - Acquisition of shares in Seibu Oil Co., Ltd.


Kawasaki Kisen, Ltd. - Share exchange with its listed subsidiary, Kawasaki Kinkai Kisen, Ltd.


Honda Motor Co., Ltd. - Strategic Alliance with Sony Group Corporation


Advantage Partners Inc. and Tokyo Century Corporation: Acquisition of Showa Denko Materials Co., Ltd.’s energy storage devices and systems business


Idemitsu Kosan Co., Ltd. - Purchase of manufacturing plant and equipment from ENEOS Corporation


Idemitsu Kosan Co., Ltd. - Agreement to fully acquire SDS Biotech K.K.


Honda Motor Co., Ltd. - Partnership with MONET Technologies Inc.


Honda Motor Co.: Agreement to establish a joint venture company in Indonesia with Panasonic Corporation


Idemitsu Kosan: Business integration with Showa Shell Sekiyu


Kawasaki Kisen Kaisha, Ltd. - Establishment of a holding company and share transfer

2017 - 2019

Acquisition of Sanyo Special Steel Co., Ltd. and Ovako AB by Nippon Steel & Sumitomo Metal Corporation


Acquisition of Japan Automobile Auction Inc. by USS Co,. Ltd.

2017 - 2018

Kawasaki Kisen Kaisha, Ltd.- Integration of container ship businesses of Japanese 3 shipping carriers to establish Ocean Network Express Holdings, Ltd.

2017 -

Toyota Motor Corporation: Successful lawsuit in Nigeria regarding trademark infringement

2015 -

Business integration between Idemitsu Kosan and Showa Shell Sekiyu

2015 - 2017

Acquisition of Nisshin Steel Co., Ltd. by Nippon Steel & Sumitomo Metal Corporation

2015 - 2016

Acquisition of Tokyo Kohtetsu by Osaka Steel

2013 - 2015

Attempted Merger between Tokyo Electron Limited and Applied Materials, Inc.

2013 - 2014

Business Integration between Sumikin Bussan and Nippon Steel Trading


Business integration between Mitsubishi Heavy Industries, Ltd. and Hitachi, Ltd. on thermal power generation systems.

2012 -

International cartel investigation into the auto shipping service sector

2011 - 2013

Merger between Nippon Steel and Sumitomo Metal

2011 - 2012

Acquisition of a railway car manufacturing company by East Japan Railway Company

2011 - 2012

Business integration with Tokyo Stock Exchange Co., Ltd. and Osaka Stock Exchange Co., Ltd.

2010 -

International cartel investigation in connection with various auto parts


Merger between Shinwa Kaiun and Nippon Steel Shipping (creation of NS United Kaiun Kaisha)