Japan and Europe: patents and trade secrets
Japanese companies hold one of the largest European patent portfolios in the world, and their advisers need a counterpart in Europe who understands their expectations, their decision-making processes and their confidentiality constraints. Dhenne Avocats offers a gateway between Japan and Europe for patents and trade secrets, built on a regular presence in Tokyo and day-to-day litigation practice before the French courts and the Unified Patent Court.
The need
The Unified Patent Court has changed the balance of European litigation: a single action can now cover a large part of the Union market, with short deadlines and powerful provisional measures. Japanese patentees must decide whether to opt their patents out, prepare to be sued and assess whether to bring proceedings. At the same time, trade secret protection in Europe relies on documented reasonable measures, which must be aligned with the group’s practices in Japan. These matters call for counsel who speaks to both cultures.
What we offer
- An opinion on the European strategy for the portfolio: opt-out, choice of forum, unitary patents, coordination with oppositions before the EPO.
- Representation before the Paris Judicial Court and the Unified Patent Court, in coordination with Japanese patent attorneys and European correspondents.
- Second opinion on a pending European dispute, written for a Japanese management team.
- A trade secret protection programme adapted to European subsidiaries and to information flows with headquarters.
- Training sessions and presentations in English on European patent litigation and on the UPC.
- A regular presence in Tokyo allowing meetings on site.
How we work
First, a scoping meeting, in Tokyo or remotely, to understand the client’s organisation and the role of its Japanese advisers. Then a written operating mode setting out languages, deadlines, reporting formats and approval channels, taking internal decision-making processes into account. Finally, each engagement has a budget per phase. The firm works in English with its Japanese clients and has a working knowledge of Japanese. In 2026, Matthieu Dhenne completed a research stay at the Institute of Intellectual Property in Tokyo, described on his profile.
Who it is for
Intellectual property departments of Japanese groups, Japanese patent attorney and law firms looking for a correspondent in Europe, European subsidiaries of Japanese companies, trading and technology companies exposed to the European market.
Frequently asked questions
Do you work directly with Japanese companies or through their advisers?
Both. Most often, the firm works alongside the Japanese patent attorney, who keeps the client relationship and the worldwide coordination of the portfolio.
What is the working language?
English for exchanges with the client and its advisers, French before the French courts and the Paris local division of the UPC, German where German proceedings require it.
Do you also act outside patents?
Yes, on trade secrets, licence and research agreements, and software copyright questions connected with patent matters.
To arrange a first conversation, contact the firm.