Keiji Isaji

Managing Partner

Keiji Isaji’s practice covers civil and criminal litigation on aircraft accidents, disputes on financial transactions, labor disputes, defamation, medical accidents, and white-collar crimes; matters regarding regulatory laws such as the Banking Law and the Financial Instruments and Exchange Law, etc., financial transactions such as sale and purchase of aircraft and various leases, and intellectual property-related matters such as licensing under Patent Law, Trademark Law, etc.


Attorney at Law, Tax Consultant


Japan (1981)


Dai-ni Tokyo Bar Association

Professional Experience

2014 – present

Sonderhoff & Einsel, Law and Patent Office

2011 – 2014

K&L Gates Gaikokuho Joint Enterprise

2001 – 2011

Clifford Chance Law Office

1981 – 2001

Tanaka & Takahashi Law Office



University of Michigan Law School (LL.M.)


University of Tokyo (LL.B.)


“Corporate Action against US Anti-trust Prosecution – Review from the De Facto Jurisdiction of Procedures for Criminal Charges and Their Background” (No. 1010 of NBL, Authors: Keiji Isaji and Atsushi Yamashita) October 2013


“License Requirements under Japanese Law on Fund Securities issued in Foreign Markets” (No. 1989 of Shouji-houmu, Co-author: Keiji Isaji) February 2013


“Case Study Financial Instruments and Exchange Act” (Edit, Jiyu Kokumin-sha Corporation) 2009


“Competition Law Seminar 2014: Enforcement of Law on International Cartel Regulation – How Can Asian Companies Deal with This from the Viewpoint of US, EU and Japan?” (Seminar in cooperation with the Japan Institute for Overseas Investment) (Tokyo, 2014, Keiji Isaji and Atsushi Yamashita)


Japanese, English