Welcome to Keisen Associates!

"Kéisén" means an "inexhaustible spring" in Japanese as we hope to become a wellspring of legal solutions for all matters relating to Japanese intellectual property law. Kéisén Associates, formerly Omori & Yaguchi, is a Tokyo-based Japanese intellectual property law firm with offices in Tokyo and Philadelphia, Pa. Our practice offers a broad range of Japanese and international legal support in patent, design, and trademark law. We offer prior art search, in-house technical translations, international licensing, as well as legal consultation for international business development and technology transfer support in Japan. Our highly skilled attorneys and patent agents are supported by a team of technical advisers, translators and administrative staff who are fluent in English. We can provide clients with a seamless, efficient, and cost effective service in all areas intellectual property protection in Japan.

Japan’s IP News


JPO’s Brand New Commissioner!

On June 16th, 2016, the successor of the Japanese Patent Office (JPO) Commissioner Ito has been announced to be Commissioner Yoshinori Komiya. As a result, Commissioner Ito is retiring from a successful career serving in Japanese government services. Commissioner Ito…
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