Atsumi & Sakai

Atsumi & Sakai is a full-service, international law firm providing one-stop legal solutions.

Comprised of around 260 Japanese lawyers, registered foreign lawyers, and foreign lawyers who work with them, forming practice groups covering all areas of corporate law, Atsumi & Sakai is a Big 6 Japanese law firm that mainly practices corporate and cross-border matters. 

We swiftly combine knowledge and insights across our practice areas, which include finance, where we have been active since our establishment, as well as M&A/investment, antitrust law, funds, labor law, IP, IT/TMT, international trade, risk management, litigation/arbitration/insolvency/business reorganization, life science, energy, and AI, to formulate a flexible response to every individual deal. Even in cutting-edge fields where no precedents exist, our lawyers bring to bear abundant knowledge and a diversity of backgrounds to support the leading pioneers at the forefront of our era.

With offices* in Tokyo, Osaka, and Fukuoka in Japan, we provide timely and precise solutions to legal concerns in all regions, in addition to actively engaging in supporting foreign companies entering Japan and local companies expanding overseas. We also provide service in German.

With overseas branch offices* in London, New York, Frankfurt, Brussels, and Ho Chi Minh City, our firm’s structure enables lawyers admitted in Japan, foreign lawyers registered in Japan and lawyers registered in foreign countries to provide timely legal services for international deals utilizing an extensive network covering approximately 120 countries and regions around the world from the Americas and Europe to the Middle East, Asia, and Africa.

*Includes affiliate offices.

(Jan. 2026)