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Ikeda & Someya

Tsuyoshi Ikeda

Tokyo, Japan Asia-Pacific Guide 2021 Ranked in 1 departments
Ranked in : Competition/Antitrust
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Lawyer Information

Lawyer profile for Asia-Pacific 2021

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Competition/Antitrust - Japan

Band 4

Tsuyoshi Ikeda leads the team at Ikeda & Someya, a boutique law firm focusing on competition and consumer advocacy. Described by sources as a "true specialist" in the antitrust space, his practices concentrates on anti-competitive behaviour and unfair trade practices.
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Lawyer information

This content is provided by Tsuyoshi Ikeda

Practice Areas

Cartels, Mergers, Joint Venture/Business Alliances, IP and Antitrust, Vertical/Distribution, False Advertising, Subcontract Act, Anti-Bribery


Admitted in Japan(2003), New York and California(2009). Worked for Kirkland & Ellis (Chicago Office) as a visiting attorney(2008-2009), Mori Hamada & Matsumoto(2009-2018).

In 2018, established Ikeda & Someya, an antitrust boutique in Tokyo. Starting with two founding partners, Ikeda & Someya has marked a rapid growth and now has more than ten attorneys in competition and consumer law areas only less than three years after its establishment.

As a former official of the Investigation Bureau of the JFTC, Yoshi has extensive experience in all aspects of antitrust/competition issues. At the JFTC, he engaged in, among others, the implementation of the leniency programme in Japan and as many as 20 dawn raids. His comments have been quoted in the most popular financial newspaper in Japan, the Nikkei, more than 50 times.

Yoshi has been an Officer of the Antitrust Committee of the IBA as the only officer from Japan since 2018, attended the Annual Meetings of ICN since 2012. He frequently serves as a main speaker at international conferences, such as the IBA and ICN.


Kyoto University(LLB, 2002). University of California, Berkeley, School of Law(Boalt Hall)(LLM, 2008).

Tsuyoshi Ikeda

Ikeda & Someya

Phone number

Yurakucho ITOCiA Office Tower 14th floor, 2-7-1 Yurakucho, Chiyoda-ku

5th Floor

2-7-4 Hirakawa-cho






Ranked In

Asia-Pacific 2021

Asia-Pacific 2020

Asia-Pacific 2017

Asia-Pacific 2016

Asia-Pacific 2015

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Total 2 contributions

Trends and Developments

Merger Control 2021 in Japan

Authors: Tsuyoshi Ikeda , Chiharu Habukawa, Shota Ogawa, Hiroko Fukushima

Law and Practice

Merger Control 2021 in Japan

Authors: Tsuyoshi Ikeda, Aya Yasui, Chiharu Habukawa, Shota Ogawa