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Tsuyoshi Ikeda

Tsuyoshi Ikeda

Ikeda & SomeyaSABO-Kaikan Annex-B 5th Floor2-7-4 Hirakawa-choTokyoJapan102-0093
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Thought Leader

WWL Ranking: Thought Leader

Questions & Answers

Tsuyoshi (Yoshi) Ikeda is a founding partner of Ikeda & Someya, an antitrust and consumer law boutique firm established in October 2018 in Tokyo, Japan. Prior to that, Yoshi served as an investigator for the Japan Fair Trade Commission (JFTC) (2005–07) and worked for Mori Hamada & Matsumoto (2009–2018). Yoshi obtained an LLB from Kyoto University and an LLM from University of California, Berkeley. He is admitted in Japan, New York and California.


I am fortunate to have gained varied and valuable experience which has enabled me to become an all-rounder of competition law. I started my career as an IP litigator. This experience has helped me to understand the complex intersection between IP and antitrust, and how people in IP departments think about competition law issues. After that, I was glad to have had the unique opportunity to work for the JFTC, where I was in charge of implementation of the leniency programme in Japan as well as heading an investigation case concerning alleged abuse of standard essential patents. In addition, I participated in around 20 dawn raids and led the hearing procedure in a false advertising case. Following the JFTC experience, I had an opportunity to study and practice in the US for two years. I am proud to be one of only a few Japanese attorneys who have had the experience of both working at the JFTC and studying abroad. In 2009, I joined MHM, one of the largest law firms in Tokyo, where I enjoyed opportunities to work for blue-chip companies both in and outside Japan not only for large-scale cartel and merger cases, but also dominance and distribution cases which required a complex analysis. I am confident that, thanks to the variety of cases I have experienced throughout my career, I am now fully ready to serve clients at my new firm with any kind of competition law case.


After practising almost exclusively on antitrust cases at MHM for several years, I noticed that there are only few antitrust boutique firms in the market. In international cartel cases, for example, we have seen non-competition law specialists represent individuals because the number of law firms with antitrust specialists has been limited. I believe that my new boutique firm will give clients more and better options than before. One significant advantage for a small boutique firm in Japan is that there is no need for extensive discovery or document production in the Japanese legal system. This means we do not have to have a large team of lawyers to handle big antitrust cases. I have seen even the biggest cartel or merger cases handled properly by just a few lawyers. This convinces me that small boutique-type law firms can properly handle large cases just as well as big firms, such as MHM. Therefore, I am confident that our new boutique, even with a small number of attorneys, can help clients with their large-scale cases in addition to smaller-scale cases such as representations of individuals. In short, I believe that there are huge, unique opportunities for our antitrust boutique to develop more customised services better tailored to the needs of our clients.


Many clients may expect we can offer our services at a lower cost than big law firms like MHM. It is true that, as a boutique with a smaller number of attorneys, we can offer our services in a more cost-efficient way. However, cost is not the only element which sets us apart from the competition. We are confident that we can offer better quality services than our competitors. I am one of the very few attorneys in the antitrust market in Japan who has the experience of working within the enforcement agency (JFTC) in addition to the experience of international practice within a big law firm. First of all, Japan does not have a “revolving door” between private practice and the antitrust agency. I am one of a few attorneys who have worked for the JFTC under the special temporary hiring programme. Among those few attorneys with JFTC experience, I have had the unique experience of studying and working abroad and have been admitted to both the NY and the CA Bar. Over 50 per cent of my work is international, including both inbound work (Japanese antitrust cases for international clients) and outbound work (cases involving foreign antitrust law for Japanese clients). Furthermore, during my nine years at MHM, I experienced every conceivable kind of antitrust case, including billion-dollar merger cases, which many antitrust lawyers at medium-sized or boutique law firms have not experienced. Making the most of my unique experience, Ikeda & Someya – as a small team – will offer personalised and “first-class” service to our clients.


You cannot be a good competition lawyer if you only know the law. Of course, it is important to have a deep understanding of competition law. But, it is just a starting point. You have to know the practice. Many clients complain that antitrust law is not very clear and has a huge grey area. It is true, therefore, that antitrust specialists have to know how the law is enforced in the real world. Generally speaking, the information in the public domain is only about the formal investigation cases which the JFTC has brought to the final conclusion. Competition law specialists, however, have to know the cases where the JFTC does not carry out a formal investigation or eventually find an infringement so that they can distinguish the borderline between legal and illegal in a huge grey area. In addition, a competition lawyer has to know the right people. First, it is important to know the right people in the enforcement agency, as they are the ones who make not only competition policy but also decisions in enforcement cases. Second, it is also important to know excellent practitioners in many other jurisdictions so that the right options are provided to clients in international cases. 

Through my unique career, I have been fortunate to have experienced many actual enforcement cases. I have also developed professional and personal relationships with excellent contacts both at the agency and at foreign law firms. Of course, I will have to continue my efforts to develop my practical experience and maintain the relationship with many people until the end of my career. This is indeed challenging, but I am enjoying this challenge.


It is true that clients expect his or her competition lawyer to be knowledgeable in competition law. However, I believe that mere knowledge is not enough to satisfy needs of clients. Many competition lawyers can point out the risks within a grey area of competition law, but – as is often the case – mere analysis does not solve the client’s problem. It is a solution, as well as hands-on assistance to reach such a solution, that a client really wants from antitrust specialists. We must be sufficiently experienced and creative to offer as many practical options as possible so that we can help clients to reach the best possible solution. One more thing: we have to act and respond quickly to a client’s request, and sometimes we should respond proactively in anticipation of a client’s need. Needless to say, it is always important for outside counsel to respond in a timely manner. But, it is even more true in an ongoing rapidly changing business environment with advanced information technologies. I am confident that my new small boutique firm is a perfect setting to offer hands-on practical services in a flexible, quick and efficient manner.  


In addition to my antitrust practice, I have been busy with many false advertising cases these days. The Consumer Affairs Agency (CAA) has been quite active and doubled the number of enforcement cases in FY2017 compared with the previous year. The amendment in 2014 requires that companies doing consumer business in Japan be equipped with adequate compliance measures to prevent false advertising. In light of these developments, false advertising regulation is now one of the hot topics many companies are paying attention to. Before the CAA was established in 2009, the JFTC was in charge of enforcement against false advertising. Because of this history, competition lawyers have been playing a key role in defending companies in false advertising cases. At the same time, it is of course important to keep up with the recent developments since the CAA was established. In this sense, I believe that our firm, Ikeda & Someya, is best positioned in the market, as we have combined my extensive experience as a defence lawyer with my partner’s insights into the CAA’s practice which he gained while he was with the CAA until recently.


We foresee several substantial changes in the Japanese antitrust practice in the coming years, all of which will increase the importance of competition lawyers. First, the JFTC envisions an amendment to the Japanese Anti-monopoly Act under which the JFTC can decide the amount of surcharges (fines) imposed in a more flexible way. Under the current law, the surcharge rate is a fixed rate stipulated under the law, and there is almost no room for the competition lawyer’s work to discount the surcharge amount. Once the amendment is implemented, companies will have to consider the strategy they will take and how best to cooperate with the JFTC in order to obtain as much discount as possible. Competition law specialists will be able to help clients in strategic decision making. In conjunction with this amendment, it is likely that attorney-client privilege protection will be also introduced for the first time in Japanese history. The introduction will change the current practice substantially and will enable companies to obtain advice from outside competition lawyers in a more comfortable way. This change also requires competition lawyers to properly protect the strategic discussion between themselves and their clients. Lastly, another amendment to our antitrust law to introduce the EU-style commitment system has already passed, and we expect that it too will come into effect in the near future. This change will also expand the room for negotiations between the company (and its attorney) and the JFTC, especially in unilateral conduct cases. So, overall, we are expecting a lot of exciting changes, each of which will substantially increase the importance and volume of our work as competition law specialists.


I believe that there will be challenging but rewarding opportunities in the future of antitrust practice. As new technologies such as big data and artificial intelligence progress, the antitrust community will encounter interesting and unknown issues. It is true that antitrust theories have developed to date in accordance with the developments in technology, but future developments seem to be more dynamic and disruptive. In the era of autonomous driving, for example, traditional car companies might compete with IT start-ups. Data collected in a particular business may play a critical role in a completely different business area. This poses an interesting question of how we can define a relevant market when we analyse antitrust cases. While antitrust practice in the future might be difficult for competition lawyers who have only been exposed to traditional cartel or merger cases, it will be fascinating for those who can live up to these ongoing changes. Writing many articles in prominent legal magazines in Japan, I am proud of being a leading antitrust specialist in introducing new antitrust issues, such as algorithm cartel and signalling cartel. Therefore, I am quite optimistic and excited to see the future development in years to come.

Global Leader

Competition 2019

Professional Biography

WWL Ranking: Thought Leader

WWL says

Tsuyoshi Ikeda is singled out as “a leading practitioner in Japan” who is celebrated for his “practical approach” to merger filings and cartel investigations.


Tsuyoshi (Yoshi) Ikeda is a founding partner of Ikeda & Someya, an antitrust boutique which was just established in October 2018.  Starting with two founding partners, Ikeda & Someya has marked a rapid growth by hiring three associates within the first seven months.

As a former official of the Investigation Bureau of the Japan Fair Trade Commission (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. Prior to establishing Ikeda & Someya, Yoshi worked for Mori Hamada & Matsumoto, one of the Big Four law firms in Japan, where he led a number of cutting-edge cases.

Yoshi has been representing multinational companies before the JFTC in international cartels and second phase review merger cases. Yoshi also advises on IP-related antitrust issues such as licensing and standard-essential patents (SEPs), making the best use of his experience in the IP/IT taskforce at the JFTC. He has additional expertise in consumer protection issues, such as false advertising, as well as anti-bribery issues.

He has been appointed as an officer of IBA’s antitrust committee since 2017. He frequently serves as a speaker at international conferences, such as the ICN (as a non-governmental adviser (NGA)) and IBA.

Yoshi is a graduate of Kyoto University (LLB, 2002) and University of California, Berkeley, School of Law (Boalt Hall) (LLM, 2008). He is admitted in Japan, New York and California. His comments have been quoted in the most popular financial newspaper in Japan, the Nikkei, more than 30 times.

National Leader

WWL Ranking: Recommended
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