Professor at College of Risk Management,

Nihon University, located in Tokyo, Japan. 


Analysis of legal issue on cyberspace, concerning privacy, information security, secrecy of communications, intermediary liability, and freedom of speech, especially associated with the impact of digitalization and the Internet.


1.    Doctor of Philosophy. Law. Chuo University, Tokyo, Japan, 2007.  Dissertation: “the Freedom of Speech and Information and Communication Law, focusing on the data flow in the Internet.” Supervisor: Prof. Masao Horibe.

2.    Master of Laws. Law. Chuo University, Tokyo, Japan, 2007.  Supervisor: Prof. Masao Horibe.

3.    Bachelor, Political Science, Waseda University, Tokyo, Japan, 1987. Supervisor: Prof. Saburo Fukuda.


1.    Senior Consultant. InfoCom Research, Inc., Tokyo, Japan, http://www.icr.co.jp/  (April 2004-October 2009).

2.    Researcher. InfoCom Research, Inc., Tokyo, Japan. http://www.icr.co.jp/  (January 1991-March 2004)

3.    Lecturer (Informaion Law). College of Law and Politics, Rikkyo University, Tokyo, Japan, http://english.rikkyo.ac.jp/academics/undergraduate/law_and_politics/ (April 2010-March 2011, April 2005-March 2006).

4.    Research Associate of Project “Communication Dynamics”. University of Tokyo Interfaculty Initiative in Information Studies Graduate School of Interdisciplinary Information Studies, Tokyo, Japan, http://www.iii.u-tokyo.ac.jp/en/ (April 2008-March 2010).

5.    Lecturer (Information Law and Policy, Social Science Studies Basics). University of Tokyo Interfaculty Initiative in Information Studies Graduate School of Interdisciplinary Information Studies, Tokyo, Japan, http://www.iii.u-tokyo.ac.jp/en/  (April 2007-March 2008).

6.    Lecturer (Internet Law). Faculty of Law, Kokushikan University, Tokyo, Japan, http://www.kokushikan.ac.jp/english/  (April 2005-March 2006).

7.    Lecturer (Privacy, Information Security, Data Flow). Department of Social and Family Economy, Faculty of Human Sciences and Design, Japan Women’s University, Tokyo, Japan, http://www.jwu.ac.jp/eng/u_programs/household_economics.html/ (April 2005-March 2006).

8.    Lecturer (Information Strategy, Data Flow and Law). Faculty of Engineering, Chiba Institute of Technology, Tsudanuma, Chiba, Japan, http://www.it-chiba.ac.jp/english/eng/index.html (April 2002-March 2004).

9.    Lecturer (Industry Study). Faculty of Economics, Tokyo Keizai University, Tokyo, Japan, http://www.tku.ac.jp/english/department/economics/  (April 2000-March 2005).

10.    Lecturer (Social Change and Institution Building). International Graduate School of Business Law, Yokohama National University, Yokohama, Japan, http://www.ynu.ac.jp/english/academics/graduate/social/index.html/  (April 1997-March 1999).


1.    Member of the Board of Content Evaluation and Monitoring Association, http://www.ema.or.jp/ema.html (since April 2008).

2.    Member of the Board of Information Network Law Association, http://in-law.jp/index.html (since September 2009).

3.    Member of Information and Communication Law Study Group, Institute for Information and Communication Policy, Ministry of Internal Affairs and Communications, http://www.soumu.go.jp/iicp/chousakenkyu/kenkyukatudou.html (since March 2008).

4.    Member of the Board of NPO The Institute of Digital Forensics, http://www.digitalforensic.jp/ (since January 2005).

5.    Director of Electronic Intellectual Property Study Group, Information Processing Society of Japan, http://www.eip.or.jp/ (since April 2010).

6.    Member of Data Protection Working Group, Cabinet Secretariat, http://www.cas.go.jp/jp/seisaku/jouhouwg/ (February 2011-June 2011).

  1. 7.    Member of Illegal and Harmful Information Working Group, Cybercrime Project, National Police Agency, http://www.npa.go.jp/cyber/csmeeting/index.html (September 2010-March 2011).

  2. 8.    Member of Personal Data Working Group under the IT Integration Forum, Ministry of Economy, Trade and Industry,  http://www.meti.go.jp/committee/kenkyukai/mono_info_service.html#it_yugo_forum_data_wg2/ (November 2012-April 2013).



1.    Introduction to Information Law; Law on Digital Network, second edition (NTT Publishing, 2011). (in Japanese)

2.    E-Discovery; Countermeasure against the Lawsuit from U.S.A., (NTT Publishing, 2010). Co-edited with Yasutaka Machimura (in Japanese)

3.    Introduction to Information Law; Law on Digital Network, first edition (NTT Publishing, 2008). (in Japanese)

Book Chapters

1.    “Freedom of Speech on Network Communications” in Keigo Komamura and Hidemi Suzuki, Freedom of Speech ; from Situations, (Shogaku-sha, 2011). (in Japanese)

2.    “Privacy and Data Protection on Enhanced Web Services” in Masao Horibe, Emerging Issues on Privacy and Data Protection, (Shojihomu 2010). (in Japanese)

3.    “Bilateral Character of Information Security and Privacy” in Ken Sakamura, Social Infrastructures of Information Established by Ubiquitous Computing, (Tokyo University Press, 2006). (in Japanese)

4.    “Content Regulation on the Internet” in Masao Horibe, Internet Society and Law, (Sinsei-sha, 2006). (in Japanese)

5.    “Information Security and Privacy” in Research Institute of Social Science of NTT Data, Law and Policy on Cyber Security, (NTT Publishing, 2004). (in Japanese)

6.    “Comparison Study of Caller ID” in Masao Horibe, Caller ID and Privacy, (NTT Publishing, 1998). (in Japanese)

Articles and Reports

1.    “Exemption of Copyright Infringement on Digital Network” 4 The Journal of Law and Politics vol. 3-4, Niigata University, February 2005. (in Japanese)

2.    “the Freedom of Speech and Information and Communication Law, focusing on the data flow in the Internet” Dissertation of Ph.D, Chuo University, March 2007. (in Japanese)

3.    ALS Scan Inc. v. Remarq Communities Inc., 239 F.3d 619 (4th Cir. 2001).” Law in America 2003-2, Japanese American Society for Legal Studies, January 2004. (in Japanese)

  1. 4.    “ISP Liability; as an intermediary ” Jurist vol. 1117, Yuhikaku, August 1997. (in Japanese)

  2. 5.    “Multimedia Application: Regulational Aspects OECD Tokyo Workshop Report, March 1996.