Treatise on Japanese Taxation, Fifth Edition (in Japanese)

Akihiro’s experience covers product liability, contractual claims, mass tort claims, and tax disputes, in various industries, in particular in the pharmaceutical and automotive industries. He has also handled disputes arising from M&A transactions, disputes involving construction sites in Asia, Africa, and the Middle East, and disputes arising from the termination of distribution agreements. He has achieved significant results in international arbitrations, including emergency arbitration proceedings under the rules of the ICC, SIAC, AAA-ICDR, and JCAA. He also advised clients in connection with US civil actions, including class actions, and Japanese judicial assistance for foreign court proceedings.

In one notable case, he successfully defended a Japanese trading company against six large vicarious liability lawsuits, involving claims totaling JPY 48.3 billion, filed by claimants including an affiliate of a US-headquartered investment bank and a US hedge fund. He also recovered JPY 13.3 billion for Shionogi & Co. in an action challenging a tax assessment relating to an in-kind contribution of a partnership interest in a cross-border reorganization for the development of a drug for AIDS. He is currently representing a pharmaceutical company in one of the largest product liability lawsuits in Japan. He is also representing a vehicle manufacturer in a case in which a large number of claimants allege that diesel emission has caused asthma.

He is a graduate of The University of Tokyo (LL.B., 1993) and Harvard Law School (LL.M., 2003), and is licensed to practice law in Japan and New York. He served as a Japanese district court judge from 1998 until 2000, and worked at Arnold & Porter (Washington, D.C.) from 2003 until 2004. He is a Fellow of the Chartered Institute of Arbitrators.

He is the author of various books and articles in the areas of litigation and international arbitration, including Yasuhei Taniguchi et al. eds., Civil Procedure in Japan (contributor, Juris Publishing). He was awarded the "Dispute Resolution Lawyer of the Year" at the ALB Japan Law Awards in 2022, and he was selected for ALB Asia Super 50 Disputes Lawyers 2025 by Asian Legal Business.

Tsuyoshi Ito has significant experience in tax counseling and tax controversies and has represented major corporations in numerous tax disputes and tax lawsuits. In March 2021, he won a significant corporate tax dispute that challenged a tax assessment of approximately USD 367 million in taxable income before the Tokyo High Court after a protracted seven-year battle. In August 2014, he won a tax dispute involving securitization transactions of domestic housing loans before the Tokyo High Court. In addition to excellent achievements in major tax disputes, he generally advises on domestic and cross-border taxation issues in various transactions, such as M&A, joint ventures, fund formation and equity/debt investments.

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.

While mainly focusing on financial transactions and financial regulations, he has also advised on a variety of projects such as international disputes regarding financial products and M&A transactions (especially those involving financial institutions). Projects he has represented include an acquisition of shares in Seiyu by KKR and Rakuten in 2021, the restructuring of KDDI’s financial business in 2020, and Aozora Bank’s capital restructuring to repay governmental funds in 2013. He won the “Deal of the Year” award at Japan Achievement Awards 2014/2015 hosted by FinanceAsia and the “Japan Deal of the Year” award at Japan Law Awards 2015 sponsored by Asian Legal Business (ALB) with respect to Suntory Holdings’ acquisition of Beam, Inc. in 2014. His practice area also includes international taxation. Taking advantage of his considerable experience in advising on international financial transactions, he provides clients with practical tax advice both at the stage of transaction structuring and during tax disputes, especially in relation to complicated financial instruments. He successfully represented Tokio Marine & Nichido Fire Insurance in contesting a tax assessment on a cross-border reinsurance transaction ceding earthquake-related risks. He is also very active in academia. He was a Visiting Associate Professor at the University of Tokyo, Graduate Schools of Law and Politics from 2010 to 2013 and has been a lecturer at Keio University Law School since 2014. He has authored numerous academic articles such as Corpus Juris Finance (Co-author; Shojihomu Kenkyukai, 2003), Comparative Income Taxation - Fourth Edition (Co-author; Kluwer Law International, 2019), and Analysis of Issue Prices in Public Offerings (Co-author; Yuhikaku, 2015).

Mayuko is an attorney at Nishimura & Asahi (admitted in Japan and New York). Her practice includes corporate matters including M&A as well as international tax and tax dispute. She has experience engaging in tax treaty negotiations and domestic procedures thereof from her time as a deputy director at the Economic Treaties Division, International Legal Affairs Bureau, Ministry of Foreign Affairs of Japan from 2017 to 2019.