Sonoda & Kobayashi Intellectual Property Law

Sonoda & Kobayashi Intellectual Property Law is a leading Japanese IP firm, which was established in 1998 and is located in central Tokyo. The firm was founded with the specific intention of creating a Japanese IP law firm with a global mindset, to foster stress-free communication and provide exceptional services. Since then, Sonoda & Kobayashi has stayed true to this goal. A unique philosophy and high standards have allowed the firm to exclusively represent leading global and domestic companies in a wide spectrum of cases, and to become one of the most trustworthy firms in Asia for the prosecution and enforcement of IP rights. In 2021 Sonoda & Kobayashi opened its new office in Beijing, from where Chinese IP-related matters are handled.

Sonoda & Kobayashi understands the importance of protecting clients’ IP rights, and the impact that these rights have on international business. They offer one-stop services for the full range of IP matters, including patent drafting and prosecution, patent litigation, utility model application, design and trademark prosecution, as well as prior art searches and strategic patent portfolio analysis. Sonoda & Kobayashi’s high patent grant rate and litigation success rate highlight the firm’s dependability for IP protection in Japan. Further, the firm is committed to obtaining the strongest protection possible during prosecution, not merely settling for a grant.

Sonoda & Kobayashi specialises in electronics, physics, mechanical engineering, software and artificial intelligence, as well as chemistry, biology and pharmaceutical sciences. With clients spanning from individual inventors and start-ups to Fortune 500 companies, Sonoda & Kobayashi represents some of the most recognisable brands across the telecoms, industrial manufacturing and pharmaceutical industries.


Sonoda & Kobayashi believes that reliable and excellent legal services in intellectual property can be provided only by having a deep understanding of complex technologies and legal issues, and this is reflected in the firm’s staff. Sonoda & Kobayashi employs more than 100 staff, including 20 patent attorneys, 17 patent engineers, US and Chinese patent attorneys, former US patent examiners, US and Australian attorneys at law, as well as many other specialised translators and support staff.

The majority of patent attorneys, engineers and technical staff at Sonoda & Kobayashi have advanced degrees in a wide range of technical fields, including 16 PhDs from prominent Japanese, Chinese and international universities. They possess technical expertise obtained from a range of backgrounds and sectors, in roles as researchers, engineers and in-house counsel at large international corporations or as staff at the Japan Patent Office. Many patent attorneys and engineers also have hands-on experience, often gained directly on factory floors, which can make a crucial difference in difficult cases.

Sonoda & Kobayashi has a dedicated in-house translation team, including 23 technical translators, many of whom have specialist backgrounds. They provide swift and thorough translations between Japanese and English, French, German and Chinese and have implemented checking systems to ensure consistency with the high quality of the firm’s original work. Further, Sonoda & Kobayashi’s team hails from 13 different countries and can offer communication in nine languages, including Japanese, English, Chinese, French, German, Italian, Dutch, Russian and Uzbek.

International perspective

Foreign clients face significant legal and linguistic barriers when prosecuting and enforcing IP rights in Japan and in China. In order to help clients overcome these barriers, Sonoda & Kobayashi encourages an open-minded, non-culturally or linguistically biased approach and provides a thorough knowledge of international patent law and technology.

In response to the issues encountered by international companies that choose to protect their intellectual property in Japan and in China, Sonoda & Kobayashi has formed a dedicated international affairs department, which comprises international attorneys and businesspeople who bridge the gap between Asian and Western cultures and practices. The international affairs department ensures that international clients benefit from clear communication and transparency, fostering mutual understanding through a client-focused and adaptable service.

Sonoda & Kobayashi is committed to continually ensuring that clients understand their IP protection situations in Japan as well as in China and benefit from the best possible patent strategy. With this in mind, the firm provides an annual patent portfolio analysis for each client, comparing their patents with those of competitors and offering valuable business insights.

Contact details

Sonoda & Kobayashi Intellectual Property Law
Shinjuku Mitsui Building
Suite 3401
2-1-1 Nishi Shinjuku
Tokyo 163 0434

Professional contacts

Other offices

  • Beijing

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