Mr Keiji Tonomura > Nagashima Ohno & Tsunematsu > Tokyo, Japan > Lawyer Profile

Nagashima Ohno & Tsunematsu
TOKYO 100-7036
Keiji Tonomura photo


Mergers and Acquisitions (M&A); IP Transactions; IT and Telecommunications; Media, Game, Entertainment and Sport; Pharmaceutical and Health Care; Data Protection and Privacy; Corporate Governance; and General Corporate.


Joined Nagashima & Ohno in 2007. Became a Partner of Nagashima Ohno & Tsunematsu in 2018. Worked as a visiting attorney at Kirkland & Ellis, Chicago (2013-14).


Japanese, English.


Daiichi Tokyo Bar Association (2007; 2014).


Kyoto University (LL.B., 2004); Kyoto University Law School (J.D., 2006); Columbia Law School (LL.M., Harlan Fiske Stone Scholar, 2013).

Lawyer Rankings

Japan > Intellectual property: Independent local firms

Nagashima Ohno & Tsunematsu covers both litigation and transactions, and has notable expertise in the technology sector, able to cover IP matters related to artificial intelligence, big data, and blockchain technology. The well regarded team attracts both major domestic and multinational clients. Core team members include Shunji Matsuda, who has more than 20 years’ experience in the practice area, and handles high value litigation matters for high profile clients. Former Tokyo District Court judge Kenji Tosaki is also key, and specialises in representing clients in litigation within the pharmaceutical industry. Keiji Tonomura is also noted for his experience on complex cross-border matters, and work within the TMT sector.

Japan > Fintech - Independent local firms

(Next Generation Partners: Bengoshi)

Keiji TonomuraNagashima Ohno & Tsunematsu

Nagashima Ohno & Tsunematsu‘s fintech team draws experienced practitioners from a number of practice fields, including financial regulations, corporate, technology and antitrust. The department benefits from this flexibility in its work assisting clients with a broad range of matters, including blockchain techology, AI, Robotics Process Automation, and biometric authentication technology. Soichiro Fujiwara and Taku Umezawa co-lead the team, with Fujiwara bringing expertise in M&A and general corporate matters, while Umezawa handles financial regulations and compliance. Keiji Tonomura has a practice which covers M&A, intellectual property, and IT transactions.

Japan > TMT: Independent local firms

(Next Generation Partners: Bengoshi)

Keiji TonomuraNagashima Ohno & Tsunematsu

Nagashima Ohno & Tsunematsu advises clients across IT, broadcasting, and telecommunication, with an aptitude for handling cutting-edge technologies and businesses. The department has a notable strength in space law, and works with both ‘Old Space’ and ‘New Space’ clients in financings, business collaborations, and contract negotiations. Soichiro Fujiwara, who has expertise in software, web service, and online gaming, co-leads the team alongside Keiji Tonomura, whose broad experience includes fintech, healthtech, cryptocurrency, robotics and AI. Ryo Okubo advises start-ups and technology companies, and is a stand out expert for space matters.