The Nikkei Legal Rankings 2025

Kozo’s anti-trust/competition practice covers every area of the practice, i.e., violation cases such as cartel and unilateral conduct, merger regulations, and compliance to prevent violations of Japanese and foreign competition laws. Kozo continues to be recognized by international law journals as one of the top practitioners in Japan in the area of competition law. He has handled large scale international cartel cases and has contributed to the realization of prominent merger regulations. In the area of international trade law, Kozo is widely recognized as a pioneer of trade law practice in Japan and has advised both the private sector and governmental agencies. He has been involved in most of the trade remedy investigations, such as those for the imposition of anti-dumping duties and subsidy countervailing duties as counsel to Japanese and foreign clients, and in some overseas trade remedy investigations to defend Japanese clients. In addition, Kozo’s practice covers international disputes, corporate crisis management, and regulatory investigations.

Kazuhiro Takei has extensive expertise representing Japanese public companies on a variety of matters, including M&A, corporate governance and digital transformation, corporate law, securities law, shareholders meeting, consumer law, and tax law. 

Asa Shinkawa has been a partner in the M&A/corporate group at Nishimura & Asahi since 2001. She has a long and successful history of advising Japanese and international corporations and private equity firms. Ms. Shinkawa has advised on mergers and acquisitions, tender offers, cross border transactions, domestic acquisitions and divestitures and going private transactions, restructurings and spin offs, joint ventures, and numerous other kinds of transactions and commercial arrangements. Ms. Shinkawa has been recognized as one of the world's leading lawyers in the field of Corporate/Mergers and Acquisitions in Chambers Global - The World's Leading Lawyers for Business, since 2009, and is ranked as one of the top practitioners in Japan in the field of Corporate/M&A. She was awarded "Dealmaker of the Year" at the ALB Japan Law Awards 2022,  "Dealmaker of the Year, North Asia" at the ALB Women in Law Awards 2021 and "Woman Lawyer of the Year" at the ALB Japan Law Awards 2020, "M&A Deal of the Year” at the IFLR Asia-Pacific Awards 2022, "Private Equity Deal of the Year” at The Asia Legal Awards 2021 and "Legal Expertise: Creating a New Standard” at the Financial Times Asia-Pacific Innovative Lawyer Awards 2019, and has received many other accolades. In addition, she has advised on M&A transactions and integrations/business combinations between public corporations in which merger control considerations were a critical prerequisite for the consummation of the transactions. Ms. Shinkawa has also advised extensively on the application of antitrust law in relation to joint ventures, business alliances and other types of cooperative arrangements between competitors, sole-distributorship arrangements, distribution agreements, dealer agreements and license arrangements. She was engaged in the reform of the electricity system in Japan, as an expert member of governmental committees under the Electricity and Gas Market Surveillance Commission  and various committees of the Advisory committees for Natural resourse and Energy of the METI from 2015 to 2021.

Yoshinobu was promoted to partner in 1999. He has experience in NP loans, real estate transactions, and equity investment cases dealing with foreign capital funds and companies. In addition to domestic M&A and business integration cases, he has recently been engaged in many M&A and JV cases by Japanese corporations in the USA, Europe, and Asian countries. He has advised Japanese corporations on lawsuits in the USA and other overseas countries, and has extensive experience in the dispute settlement and risk management fields. He has won many awards in the Corporate/M&A, Private Wealth and Healthcare fields from business law reviews, such as Chambers Global and The Legal 500 Asia-Pacific.

Mr. Ota has a wealth of practical international and domestic legal experience, focusing on the areas of hostile takeovers, shareholder activism, M&A transactions (including cross-border deals), corporate governance and other corporate matters, domestic/international taxation, and personal information/data protection, and works on a wide range of corporate legal affairs cases. In the NIKKEI’s "Most Successful Lawyers" awards he was ranked in the corporate law category (1st) and the tax category (2nd) in 2024; in the corporate law category (1st) and the M&A category (1st) in 2023; and in the corporate law category (1st) in 2022. In addition, he dedicates himself to research and writing activities that bridge academia and legal practice on cutting-edge issues related to the Companies Act, the Financial Instruments and Exchange Act, tax law, the Act on the Protection of Personal Information, etc. He has edited and authored many books and papers, such as "Introduction to Corporate Governance" (Iwanami Shinsho), "Hostile Takeovers and Activists" (Iwanami Shinsho), “Schemes and Tax Issues of M&A and Corporate Restructuring, 4th Ed.”, “Corpus Juris M&A - Completely Revised Edition (first volume) (second volume)”, “Handbook on Share Options (Fifth Edition)”, “Corpus Juris Series - Personal Information Protection Legislation (Global)”, “Handbook on Class Shares”, etc.

Mr. Kimeda’s main areas of practice are Corporate Crisis Management and Litigation. As for Corporate Crisis Management, he has extensive experience in corporate scandal cases, including window-dressing, misrepresentation of financial statements, insider trading, antitrust (bid rigging, price cartels, and abuse of dominant position), product defects, misleading representations of products, divulging confidential information, bribery, political funding, money laundering, breach of industrial regulations, and factory accidents. In these types of cases he has specific expertise on the issues of internal investigations, third party committee investigations, defending against criminal and administrative investigations, public relations, rebuilding compliance systems, reforming corporate governance, and handling the related civil litigation. He also serves as an outside whistleblower hotline channel for a number of companies. As for litigation, he has considerable experience in tax disputes, shareholders disputes, and other types of corporate litigation. He is the author of numerous legal articles and has also been involved in the process of making laws and regulations. He has been recognized as one of the “Most successful lawyers” by the NIKKEI for the last several years as below.

2025 Compliance category 2nd
2023 Corporate Crisis Management category 1st
2021 Corporate Crisis Management category 1st
2020 Corporate Crisis Management category 1st
2018 Corporate Crisis Management category 2nd
2014 Corporate Crisis Management category 2nd
2011 Corporate Crisis Management category 3rd
2024 Corporate Legal Affairs category 17th
2022 Corporate Legal Affairs category 9th
2016 Corporate Legal Affairs category 10th
2015 Corporate Legal Affairs category 8th
2013 Corporate Legal Affairs category 2nd
2012 Corporate Legal Affairs category 4th

Kei Umebayashi is a partner at Nishimura & Asahi and previously worked at the Special Investigative Section of the Tokyo District Public Prosecutors Office, where he obtained extensive experience and know-how in criminal investigations.
 He is expert at gathering evidence and conducting hearings.
 He mainly handles cases in which the executives or officers of a company leaked, intentionally or accidentally, the company’s confidential information, including customer data and business secrets.
 He deals with matters conducted by Japanese authorities, including the Securities and Exchange Surveillance Commission (SESC) and the Fair Trade Commission.
 Additionally, he gives valuable advice concerning a variety of other matters, such as insider trading, antitrust law, leniency applications under antitrust law, and inquiries by the US Department of Justice, European Commission and other foreign authorities when a company is targeted by them due to alleged violations of antitrust laws.

Yuki Oi is a partner in our M&A/Corporate practice group. He advises domestic and international corporations and financial institutions on their cross-border and domestic M&A transactions. He also handles corporate governance matters and general corporate issues, as well as corporate crisis management matters and commercial litigation.
 
 Some of the major cases he has advised on include representing UFJ Holdings on its integration with Mitsubishi Tokyo Financial Group (2006), Bulldog Sauce on its famous defense against a hostile takeover attempt initiated by Steel Partners (2007), the Osaka Securities Exchange on its integration with the Tokyo Stock Exchange (2011), Idemitsu Kosan on its integration with Showa Shell Sekiyu (2015-19), Toshiba on its divestiture of Toshiba Memory Corporation (2018), and Honda on its strategic alliance with Sony Group in mobility sector (2022).
 
 He was awarded the Young Lawyer of the Year Award at the ALB Japan Law Awards 2019, and the Innovative Practitioners Award at the FT Innovative Lawyers Awards Asia-Pacific 2020. He was also selected as one of Asia’s top 40 lawyers under 40 by Asian Legal Business in 2017.

 He has also served as a lecturer at the University of Tokyo, Faculty of Law (2012-13), and as a lecturer (2014-24) and a Visiting Professor (2025-present) at the University of Tokyo, Graduate Schools for Law and Politics.

Since joining the firm, Mitsuhiro Harada has been actively involved in Mergers & Acquisitions and has represented Japanese or non-Japanese buyers or sellers in numerous cross-border transactions in varied industries, including stock and asset acquisitions, private equity and venture capital investments, joint ventures and strategic alliances. He has recently become deeply engaged in international transactions, particularly in assisting Japanese companies with expanding into East and South East Asian markets. In addition, he has provided a broad range of legal services in the field of general corporate matters, including corporate governance issues and civil or commercial disputes.

In the area of Robotics/Artificial Intelligence, Shin Fukuoka mainly handles AI, Big Data and IoT. He acts as a Member of The Cabinet Office’s “Committee on Human-centered AI Social Principles” and Committee Member of the Ministry of Economy, Trade and Industry Investigative Commission on "The AI and Data Contract Guidelines Review Committee". He has also contributed to many publications, including "Law and Strategy of the Internet of Things and Artificial Intelligence", "Artificial Intelligence: Law and Issues" and "Data Contract Law". In the area of Corporate, he mainly handles M&A and Corporate Governance. In the area of Restructuring/Insolvency, he has been involved in numerous restructuring and insolvency cases, with a focus on cross-border insolvency cases, representing both debtor parties and creditor parties. Most recently, he represented Daiichi Chuo Kisen Kaisha and Japan Airlines as a legal counsel of the debtor and Elpida, Takefuji and Mt.Gox as a creditor’s counsel. He has also handled a number of real estate related disputes.

His main practice area is corporate crisis management and litigation. He is also highly knowledgeable and experienced on matters involving foreign investigations and regulatory authorities. He has dealt with many cases in relation to investigations by the Securities and Exchange Surveillance Commission, the Japanese Fair Trade Commission, the Japanese Public Prosecutor’s Office, etc., as well as foreign authorities such as the U.S. Department of Justice. He has also dealt with a variety of cases such as misconduct by executives and employees, violation of environmental regulations, violation of the regulation regarding pharmaceutical and medical equipment, etc. In addition to cases that require emergency responses, he has advised many companies to build effective whistleblowing systems and anti-bribery compliance programs, and he has assisted with due diligence procedures from a compliance perspective.

Noriya advises national and international clients from various industries, with a focus on multi-national data protection law projects, such as drafting policy, data transfer agreements and out-sourcing agreements, IT compliance questions, and data breach issues. Since he has experience working with local counsel in more than 80 jurisdictions, he has in depth knowledge of the similarities and differences among data protection laws in many jurisdictions. He can provide his advice taking into account the difference of Japanese laws and other main data protection laws such as the GDPR, CCPA, and PIPL (China).

He graduated from the University of Tokyo Graduate School of Frontier Sciences (M.S.) in 2004. Due to his technical background, he advises clients on various technology matters, including artificial intelligence (AI), generative AI, data protection, data utilization, medical field, healthcare, software, systems, cloud computing, OSS, information technology, DX, and quantum computing. His time at the Akira Hirose laboratory at the University of Tokyo provided him with deep knowledge of artificial intelligence (AI) and generative AI because he studied neural networks, which is the main technology of artificial intelligence (AI) and generative AI. He successfully passed the Japanese patent attorney examination in 2002, and he has been admitted in Japan since 2009. He advises clients on various intellectual property law matters due to his technical background and knowledge as a Japanese patent attorney. Regarding dispute matters related to intellectual property, he has handled patent litigation, litigation regarding employee inventions and trade secret litigation, among others. He especially has considerable experience in trade secret disputes, and he provides a support service on countermeasures against divulging trade secrets, including drafting company regulations, data management practice, and employee training.

Yoshi’s practice covers various M&A transactions, cross border deals, and day-to-day commercial businesses, with a focus on Europe-related matters. He lived in Europe approx. 8 years including studying at the master of law at UCL in London, working approx. 3 years in leading firms in Frankfurt, Paris and Italy, a short secondment in Barcelona/Madrid and having regular business trips all across Europe including the Netherlands, Nordic countries and Eastern Europe. As a leading partner of Europe practice and cross-border team, Yoshi provides a tailored legal services in a timely and flexible manner.

*Legal advice in the UK is provided under the name of Nishimura & Asahi UK Limited, a legal entity independent from, and a subsidiary of, Nishimura & Asahi (Gaikokuho Kyodo Jigyo). None of Nishimura & Asahi (Gaikokuho Kyodo Jigyo), Nishimura & Asahi UK Limited or, the representative, Yoshiyuki Kizu is authorized by the Solicitors Regulation Authority for England and Wales, and none will undertake any reserved legal activity as defined in the United Kingdom Legal Services Act 2007.