Nagashima Ohno & Tsunematsu is widely recognised for representing major domestic and international corporations in high-stakes, complex disputes. The firm’s litigation and arbitration practice spans proceedings before Japanese courts, as well as international arbitration and mediation forums. The team brings deep expertise across a broad range of specialised areas, including commercial transactions, intellectual property, taxation, product liability, securities, and consumer protection. At the helm, Koki Yanagisawa leads the practice with a strong focus on disputes involving commercial, antitrust, and employment law. He has acted for a diverse portfolio of Japanese and global clients across multiple sectors in litigation, arbitration, and mediation. Yoshimi Ohara is a prominent figure in international arbitration, regularly acting under institutional rules such as ICSID, SIAC, ICC, AAA/ICDR, and JCAA. Her cross-border experience makes her a key adviser in globally sensitive matters. Yoshihiro Takatori brings further depth to the team with his focus on international litigation and alternative dispute resolution, reinforcing the firm’s ability to manage disputes that require multi-jurisdictional strategy and coordination.
Legal 500 Editorial commentary
Accolades
Client satisfaction: Lawyer & team quality
Client satisfaction: Sector knowledge
Testimonials
Collated independently by Legal 500 research team.
‘Nagashima Ohno & Tsunematsu has a leading practice in both domestic and international arbitration, with particular strength in complex, high-value cross-border disputes. The team has extensive experience under major institutional rules, including ICC, SIAC and JCAA, and is recognised for its strategic advocacy, tribunal insight, and procedural expertise.'
‘Yoshimi Ohara stands out for her exceptional professionalism, procedural expertise, and depth of experience in international arbitration. She demonstrates a proactive and timely approach to case management, ensuring efficiency without compromising fairness.'
‘From my experience, this firm's thoroughness, attention to detail, and constant vigilance in thinking through and being prepared for every possibility sets them apart from other law firms.’
‘I would commend Hironobu Tsukamoto, Masashi Chusho, and Keni Tosaki as standout lawyers at the firm in IP. Their knowledge of Japanese and U.S. patent law is very impressive. Their ability to appreciate cross-border challenges with gathering evidence is also well appreciated.’
‘As one of Japan’s Big 4 firms, this team is highly regarded for its expertise in arbitration and litigation, including international disputes. Their strengths lie in deep legal knowledge, strategic thinking, and extensive experience with cross-border matters. Clients value their proactive approach, clear advice, and strong track record in complex cases.'
‘Yoshimi Ohara stands out for her exceptional expertise in both domestic and international arbitration. She is highly knowledgeable, practical, and always responsive to client needs. Her ability to handle complex cases with clarity and composure distinguishes her from competitors, and her strategic insights are highly valued.
Key clients
- Central Japan Railway Company
- Tokyo Electric Power Company
- Kajima Corporation
- Nissan Motor Co., Ltd.
- SECOM Co., Ltd.
Work highlights
Representing Tokyo Electric Power Company (TEPCO) in its shareholders derivative litigation.
Representing Central Japan Railway Company (JR Central) in its Linear Chuo Shinkansen litigation.
Lawyers
Leading partners: Bengoshi
The strongest partners in their field, leading on market-leading deals and endorsed by peers and clients alike.
Yoshihiro Takatori
Practice head
Koki Yanagisawa
Other key lawyers
Yoshimi Ohara; Yoshihiro Takatori; Hironobu Tsukamoto; Masashi Chusho; Keni Tosaki