GAR 100 - 16th Edition

Mori Hamada and Matsumoto

Mori Hamada and Matsumoto

Professional notice

Advising on a multibillion dispute over a retail joint venture

People in Future Leaders1
Pending cases as counsel8
Value of pending counsel workUS$3.1 billion
Treaty cases as counsel0
Third-party funded cases0

Mori Hamada & Matsumoto is one of Japan’s Big Four law firms. Its predecessor firm Mori Sogo Law Offices was the largest dispute resolution-focused firm of its day.

The Tokyo office is home to well-regarded partner Mugi Sekido, a director of the Japan Association of Arbitrators; and Yoshinori Tatsuno, who joined in 2016 and is deputy secretary general at the Japan International Dispute Resolution Center and sits on ICC Japan’s Arbitration Committee.

The firm has said it is committed to developing a full international arbitration practice as Japanese firms increasingly act as lead counsel in arbitrations rather than instructing international firms.

To that end, it has recruited arbitration practitioners qualified in Singapore, Thailand and Malaysia as well as major Western jurisdictions.

One of those is US national Daniel Allen in Tokyo – recruited from Freshfields Bruckhaus Deringer in Tokyo and promoted to become the firm’s first foreign disputes partner in 2021.  Canadian and English-qualified counsel Colin Trehearne also joined the office in that year, having worked at Herbert Smith Freehills and Boies Schiller Flexner.

Other partners to know are Seri Takahashi in Singapore, who worked at Freshfields and Hogan Lovells; barrister Nathee Silacharoen in Bangkok; and former Kirkland & Ellis lawyer Kana Manabe, who splits her time between Singapore and Yangon.


Most of the arbitration team is in Tokyo with others in Singapore, Bangkok and Yangon. The wider firm has a presence in four other Japanese cities as well as Beijing, Shanghai, Ho Chi Minh City and Hanoi. In early 2023, it also announced the launch of an office in New York and an alliance with a firm in Jakarta.

Who uses it?

The firm advises Japanese clients such as Hitachi, Toshiba, SoftBank, Japan Post, Yamato Transport, Bic Camera, Coincheck and Daio Paper Corporation. It is also known to have acted for Norwegian export finance institution Eksportfinans ASA.

Track record

For Hitachi, the firm teamed up with Allen & Gledhill to defeat a SIAC claim by Korean engineering company POSCO ICT over new railway infrastructure in Ho Chi Minh City. POSCO’s claim for termination was dismissed and Hitachi won a US$52 million counterclaim.

The firm defended Japanese consumer electronics company Funai Electric against a claim by Dutch technology group Philips over a collapsed deal to sell off part of its audio and visual devices business.

Recent events

Mori Hamada has acted alongside Korean firm Jipyong in two billion-dollar disputes over a retail joint venture at the Japan Commercial Arbitration Association (JCAA). In 2021, it won an award concerning a US$1 billion share purchase that spawned Tokyo set-aside proceedings and Korean litigation. The firm is advising on a second proceeding over a share purchase valued at more than US$3 billion. Tatsuno and Allen lead the team.

In another case at the JCAA, alongside Indian firm Khaitan & Co, Allen represented two electronics manufacturers in a US$10 million dispute over an Indian joint venture. They won a final award that refused to restrain the clients from complying with obligatory actions under Indian law.

The firm’s ICC instructions include acting for solar power plant owners in a US$20 million dispute with a Spanish construction contractor. The owners are seeking liquidated damages for delays and are defending a counterclaim.

It advised a Singapore metals company on its US$70 million English-law ICC claim over a commercial sales relationship with one of Japan’s largest companies. The client, which saw the dispute as a bet-the-company case, achieved a settlement just before the final merits hearing.

In 2022, partner Yuko Kanamaru in Tokyo left the firm after 16 years to join Japanese firm Gaien Partners (where another former Mori Hamada arbitration partner, Junichi Tobimatsu, is based).

Chia Chi Chong, an ex-Drew & Napier lawyer who is English-Chinese-Malay qualified, was promoted to partner in the Singapore office.

Japanese arbitration’s rising star

Our practice is young, dynamic, and taking the Japanese arbitration market by storm. Just four years after beginning our investment in this field by recruiting Daniel Allen (ranked in Who’s Who Legal as among the “most highly regarded” rising stars in Asia) from one of the world’s most storied international arbitration practices, we have already managed to secure a place as one of just two Japanese law firms in GAR100.

We believe that the key to our success is that our team is offering the Japanese market a new product. By combining the sharpest Japanese-qualified disputes lawyers with a growing team of non-Japanese arbitration specialists trained at the highest echelons of international legal practice, we are able to meet the exacting service standards that our clients expect and rely upon while also achieving our clients’ business objectives (including, of course, winning cases).  


The focus of our international arbitration practice is acting as lead counsel in high-value international arbitration matters. We act across all major sectors and industries, including natural resources, renewable energy, pharmaceuticals, high-technology, finance (including cryptocurrency and blockchain), investment, and construction. We have particular expertise in disputes relating to joint ventures, EPC projects, M&A, and intellectual property.

Our team has represented clients in arbitrations and emergency arbitrations under a wide range of arbitral rules, including popular choices in Asia, such as ICC, SIAC, JCAA, UNCITRAL, ICSID, CIETAC, THAC, VIAC, and others. Our team members also sit as arbitrators.

Our practice also sees us partner with leading firms by taking leading partner roles on matters seated in Japan or governed by Japanese law.

Finally, we are proud to say that our team’s depth of experience arguing cases as counsel in investment treaty arbitrations is second to none in Japan. That experience includes, uniquely among our peers, acting not just for investors, but for States as well.

Points of contact

To learn more about our practice and how we can help you, please contact the individuals listed below. We look forward to hearing from you.

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