Press Releases
Sidley Adds Senior Partners Simon Barrett and Olivia Matsushita to Tokyo Office
March 16, 2026
Tokyo – Sidley is pleased to announce that Simon Barrett and Olivia Matsushita have joined the firm as partners in its Energy, Transportation, and Infrastructure practice in Tokyo.
Mr. Barrett joins Sidley from Pillsbury Winthrop Shaw Pittman LLP, where he was Pillsbury’s Senior Partner in Japan and head of the firm’s Finance and Energy & Infrastructure practice in Japan. Ms. Matsushita also joins from Pillsbury Winthrop Shaw Pittman LLP, where she was Managing Partner of the firm’s Tokyo office and a partner in their Finance and Energy & Infrastructure practice.
Mr. Barrett has more than two decades of experience advising sponsors, strategic investors, private equity funds and lenders on complex, high-value, cross-border transactions in the energy and infrastructure sectors and will serve as co-managing partner of the Tokyo office. His practice spans major projects and investments, including project development, project finance, cross-border mergers and acquisitions, joint ventures, private equity investments, restructurings, and related dispute resolution.
Ms. Matsushita has a broad practice covering cross-border energy and transportation, acquisition finance, project finance, and the financing of movable assets using a range of sophisticated structures. She is a trusted adviser to debt and equity arrangers on JOL and JOLCO financings involving Airbus and Boeing aircraft as well as engines for carriers operating in Oceania, South-East Asia, Europe, the United Kingdom, and the United States.
Mr. Barrett and Ms. Matsushita are recognized as leading lawyers in Japan across multiple practice areas, including Projects & Energy: International; Construction; and Banking & Finance: International Asset Finance in both Chambers & Partners and Legal 500.
“Japan is a core hub for significant cross-border deal flow. By adding Simon and Olivia, we will strengthen our ability to serve international clients and help them unlock new opportunities in the region and beyond,” said Yvette Ostolaza, Sidley’s Management Committee Chair. “Expanding our cross-border energy and infrastructure offering remains a key priority for the firm, following the recent additions of Alun Evans in Singapore, John Thomas in New York, and Steven Tredennick and Paris Theofanidis in Houston.”
“Simon and Olivia are market-leading lawyers known for their deep experience in cross-border work in energy, infrastructure, and finance. These are transformational hires for our Tokyo office and for our broader Asia-Pacific expansion,” said Constance Choy, managing partner of Sidley’s Asia-Pacific region and a member of the firm’s Management and Executive Committees. “Both are the go-to lawyers for both inbound and outbound energy investment for many multinational companies based in Japan and I know our colleagues are excited to start working with them on cross-border matters.”
Sidley’s Energy, Transportation, and Infrastructure practice offers broad experience advising clients in the energy, digital media, transportation, and logistics industries, ranging from transactional, regulatory, and litigation support. Sidley is also ranked Band 1 USA - Nationwide Energy Transition in the most recent Chambers rankings. Lawyers in the practice have been recognized as leading practitioners by Chambers, Who’s Who Legal, The Legal 500, Project Finance International, IFLR, and Euromoney.
Mr. Barrett and Ms. Matsushita join Sidley’s long-established Tokyo office, having been founded nearly 40 years ago in 1988. The office handles cross-border transactions and advises clients on Japanese outbound and inbound deals. The office also advises clients on navigating the complex regulatory regimes in Japan and represents Japanese clients on regulatory, litigation, and enforcement matters in the United States and around the globe.
Sidley is an elite global law firm. With approximately 2,300 lawyers and 160 years of experience, we have established a reputation for deploying innovative legal strategies to achieve powerful results for our clients in complex transactional, restructuring, crisis management, investigation, regulatory, and litigation matters.
Our perspective and reach are truly global, supported by 21 offices strategically situated in key commercial, regulatory, and financial centers across the world. Our lawyers and business professionals, fluent in more than 75 languages, possess the cultural awareness and cross-border legal acumen needed to bring clarity to a dynamic business landscape.
Attorney Advertising—Sidley Austin LLP is a global law firm. Our addresses and contact information can be found at www.sidley.com/en/locations/offices. Sidley and Sidley Austin refer to Sidley Austin LLP and affiliated partnerships as explained at www.sidley.com/disclaimer.
Mr. Barrett joins Sidley from Pillsbury Winthrop Shaw Pittman LLP, where he was Pillsbury’s Senior Partner in Japan and head of the firm’s Finance and Energy & Infrastructure practice in Japan. Ms. Matsushita also joins from Pillsbury Winthrop Shaw Pittman LLP, where she was Managing Partner of the firm’s Tokyo office and a partner in their Finance and Energy & Infrastructure practice.
Mr. Barrett has more than two decades of experience advising sponsors, strategic investors, private equity funds and lenders on complex, high-value, cross-border transactions in the energy and infrastructure sectors and will serve as co-managing partner of the Tokyo office. His practice spans major projects and investments, including project development, project finance, cross-border mergers and acquisitions, joint ventures, private equity investments, restructurings, and related dispute resolution.
Ms. Matsushita has a broad practice covering cross-border energy and transportation, acquisition finance, project finance, and the financing of movable assets using a range of sophisticated structures. She is a trusted adviser to debt and equity arrangers on JOL and JOLCO financings involving Airbus and Boeing aircraft as well as engines for carriers operating in Oceania, South-East Asia, Europe, the United Kingdom, and the United States.
Mr. Barrett and Ms. Matsushita are recognized as leading lawyers in Japan across multiple practice areas, including Projects & Energy: International; Construction; and Banking & Finance: International Asset Finance in both Chambers & Partners and Legal 500.
“Japan is a core hub for significant cross-border deal flow. By adding Simon and Olivia, we will strengthen our ability to serve international clients and help them unlock new opportunities in the region and beyond,” said Yvette Ostolaza, Sidley’s Management Committee Chair. “Expanding our cross-border energy and infrastructure offering remains a key priority for the firm, following the recent additions of Alun Evans in Singapore, John Thomas in New York, and Steven Tredennick and Paris Theofanidis in Houston.”
“Simon and Olivia are market-leading lawyers known for their deep experience in cross-border work in energy, infrastructure, and finance. These are transformational hires for our Tokyo office and for our broader Asia-Pacific expansion,” said Constance Choy, managing partner of Sidley’s Asia-Pacific region and a member of the firm’s Management and Executive Committees. “Both are the go-to lawyers for both inbound and outbound energy investment for many multinational companies based in Japan and I know our colleagues are excited to start working with them on cross-border matters.”
Sidley’s Energy, Transportation, and Infrastructure practice offers broad experience advising clients in the energy, digital media, transportation, and logistics industries, ranging from transactional, regulatory, and litigation support. Sidley is also ranked Band 1 USA - Nationwide Energy Transition in the most recent Chambers rankings. Lawyers in the practice have been recognized as leading practitioners by Chambers, Who’s Who Legal, The Legal 500, Project Finance International, IFLR, and Euromoney.
Mr. Barrett and Ms. Matsushita join Sidley’s long-established Tokyo office, having been founded nearly 40 years ago in 1988. The office handles cross-border transactions and advises clients on Japanese outbound and inbound deals. The office also advises clients on navigating the complex regulatory regimes in Japan and represents Japanese clients on regulatory, litigation, and enforcement matters in the United States and around the globe.
Sidley is an elite global law firm. With approximately 2,300 lawyers and 160 years of experience, we have established a reputation for deploying innovative legal strategies to achieve powerful results for our clients in complex transactional, restructuring, crisis management, investigation, regulatory, and litigation matters.
Our perspective and reach are truly global, supported by 21 offices strategically situated in key commercial, regulatory, and financial centers across the world. Our lawyers and business professionals, fluent in more than 75 languages, possess the cultural awareness and cross-border legal acumen needed to bring clarity to a dynamic business landscape.
Attorney Advertising—Sidley Austin LLP is a global law firm. Our addresses and contact information can be found at www.sidley.com/en/locations/offices. Sidley and Sidley Austin refer to Sidley Austin LLP and affiliated partnerships as explained at www.sidley.com/disclaimer.
Media Contact
Matt MessingerDirector, Public Relations+1 312 456 4009 (Global)
Contacts
Offices
Capabilities
Suggested News & Insights
Sidley Represents Kodiak Gas Services in US$1 Billion Senior Notes OfferingMarch 16, 2026Infocast Solar + Wind Finance & Investment SummitSunday, March 15, 2026 - Wednesday, March 18, 2026Sidley Partner Ken Irvin to Present at WSPP’s Spring 2026 Operating Committee MeetingWednesday, March 11, 2026 - Friday, March 13, 2026Sidley Represents Siris in Its Agreement to Acquire a Majority Stake in TAKKIONMarch 10, 2026Sidley Advises Diversified Energy Company on Secondary Offering of Common SharesMarch 10, 2026Parent Company Liability Under the Clean Air Act: Federal District Court Applies Bestfoods and Imposes $100 Million Penalty and $20 Million in MitigationMarch 6, 2026
- Stay Up To DateSubscribe to Sidley Publications
- Follow Sidley on Social MediaSocial Media Directory

