Managing Partner
Satoshi Hirota
Satoshi Hirota specializes in mergers and acquisitions (M&A) and investment transactions, including structuring, legal due diligence, contract negotiation, general corporate legal matters (such as listed company governance), IPO preparation, and dispute resolution, primarily under corporate law. Drawing on his broad business experience—including roles at a major international law firm, as an M&A and finance specialist, and as an investment and management advisor at a private equity fund—he provides legal services that are closely aligned with practical business realities. He also serves as an outside director for a publicly listed company.
Main Practice Areas
With deep experience in M&A transactions—including front-line roles at investment funds—Satoshi provides strategic negotiation support and practical guidance throughout due diligence and contract drafting.
- Founder-led sales of owner-managed companies (sell-side)
- Startup exits (sell-side)
- Business succession transactions by investment funds (buy-side)
- Acquisitions by operating companies (buy-side)
- Corporate reorganizations, including mergers and company splits
With one of Japan’s most extensive track records in this field, Satoshi offers market-informed insight and negotiation support. He proposes optimal structures tailored to a broad range of investment models.
- Fundraising by startups (issuer-side)
- Startup investments by venture capital and corporate venture capital firms (investor-side, including many lead counsel roles)
- Silent partnership (tokumei kumiai) investment transactions
- Corporate governance and compliance
- Whistleblower response
- Investigation committee support
- Contract review
- Internal policy and organizational development
Satoshi handles corporate disputes with a focus on resolving matters in line with clients’ broader business objectives.
- Shareholder meeting resolution nullification litigation
- Litigation for inspection of accounting books
- Intellectual property litigation
- Other corporate litigation
- Extensive experience in pre-litigation dispute negotiation
Education & Professional Background
2001 | LL.B., Kyoto University |
2002–2008 | Associate, at a major international law firm (Tokyo) |
2008 | LL.M., Duke University School of Law |
2008–2009 | Associate, at a U.S.-based international law firm (Dallas & New York) |
2009–2014 | Investment & Management Support, at an independent private equity fund |
2014–2015 | Head of Administration & Services, at an IT venture company |
2015-Present | Founded HCA Law Office (Managing Partner) |
Memberships
- Dai-ni Tokyo Bar Association
- Business Succession Study Group (Dai-ni Tokyo Bar Association)
- Japan In-House Lawyers Association
Lectures & Publications
Lectures
- "Latest Trends in M&A and Practical Defensive Strategies – TOB, MBO/LBO, Going Private, New Corporate Law, and Takeover Defense Measures," Financial Facsimile News Seminar (Co-presenter, November 2005)
- "Why Are Buyouts by Investment Funds Effective for Business Succession?" Tokyo Appraisal Seminar for Accountants and Tax Advisors – Essentials of Inheritance and Business Succession (Co-presenter, 2012)
Partner
Masahiko Shimizu
Masahiko Shimizu has been a licensed attorney since 2003. During the first decade of his career, he primarily served as legal counsel to financial institutions, securities firms, fund managers, and other institutional investors. His practice focused on capital markets transactions and the structuring of various financial instruments, along with handling numerous legal due diligence matters related to M&A financing.
Since launching his own practice in 2014, Masahiko has continued to provide legal services grounded in his strong financial expertise while broadening his scope to include advisory work for small and medium-sized enterprises (SMEs) seeking IPOs, engaging in M&A transactions, and resolving disputes through both negotiation and litigation.
Main Practice Areas
- Venture Law / Startup Legal Support
- Finance
- Mergers & Acquisitions (M&A)
- Litigation / Dispute Resolution
- Financial Instruments and Exchange Act / Securities Market Disclosures
- Employment and Labor Compliance
- Aviation Law
Education & Professional Background
2002 | B.A. in Economics, The University of Tokyo |
2002–2003 | Legal apprentice (judicial training) |
2003–2014 | Associate, Mitsui, Yasuda, Wani & Maeda Law Office (2005- Mitsui Company) |
2014 | Established independent practice |
2017-Present | Partner, HCA Law Office |
Memberships
- Dai-ni Tokyo Bar Association
Lectures & Publications
Lectures
- "Amendments to the Specially Permitted Business for Qualified Institutional Investors – Understand the 2016 Legal Reform in Three Hours," Financial Facsimile News Seminar (Co-presenter, June 2016)
Partner
Ken Takako
Ken Takako brings deep expertise in corporate legal practice, particularly in the areas of M&A and finance. He provides comprehensive legal support that includes drafting and reviewing contracts and advising on a wide range of matters involving the Financial Instruments and Exchange Act, the Companies Act, labor and employment law, antitrust law, and intellectual property law. His core strengths lie in M&A transactions—including due diligence, contract negotiation, and post-merger integration—as well as financial regulations affecting securities firms, investment management companies, private equity funds, venture capital, and hedge funds. He also serves as an outside director for several companies.
Main Practice Areas
- Mergers & Acquisitions (M&A)
- Finance
- Funds / Investment Management
- General Corporate
Education & Professional Background
2000 | LL.B., The University of Tokyo |
2003–2004 | Mitsui, Yasuda, Wani & Maeda Law Office |
2004–2017 | Oh-Ebashi LPC & Partners (2012– Partner) |
2013 | LL.M., Duke University School of Law |
2013–2014 | Davis Polk & Wardwell LLP (New York & Tokyo) |
2016–2023 | Adjunct Lecturer in Business Law (Finance Law), Tokyo University of Foreign Studies |
2017–Present | Partner, HCA Law Office |
Memberships
- Daini Tokyo Bar Association
Lectures & Publications
Publications
- "Relaxation of Regulations on Investment Management Business and Compliance," Ginko Jitsumu, April 2023, Ginko Kenshu Sha
- Learning Civil Code Reform Through Case Studies (Co-author), Shoji Homu, May 2018
- Legal Practices for Financial Institutions: 5000 Topics (Co-author), Kinyu Zaisei Jijyo Kenkyukai, February 2018
- "Legal Considerations in Contracting ‘Specified Deposits’," Financial Compliance, Vol. 39, No. 12, December 2009, Ginko Kenshu Sha
- Article-by-Article Commentary on the Shinkin Bank Act (Co-author), Kinyu Zaisei Jijyo Kenkyukai, September 2007
Lectures
- "Amendments to the Specially Permitted Business for Qualified Institutional Investors and Practical Responses — An Overview from the Drafter’s Perspective," Kin-yu Faximile News, March 2016
- "Outline of 2015 Amendments to the Financial Instruments and Exchange Act (Review of Specially Permitted Business for Qualified Institutional Investors)," Oh-Ebashi LPC & Partners, February 2016
- "Impact of Civil Code Reform on Corporate Legal Practices," Westlaw Japan / Oh-Ebashi LPC & Partners, February 2016
- "Impact of Civil Code Reform on Financial Practices," Westlaw Japan / Oh-Ebashi LPC & Partners, January 2016
- "Recent Reforms and Key Cases Regarding Insider Trading Regulations," Westlaw Japan / Oh-Ebashi LPC & Partners, February 2015
- "Recent Revisions to the Tokyo Stock Exchange Listing Rules," Oh-Ebashi LPC & Partners, July 2010
- "Regulations on Private Investment Funds under the Financial Instruments and Exchange Act," Seminar Info Co., Ltd., June 2008
- "Regulations on Investment Advisory and Management Business under the Financial Instruments and Exchange Act – Based on Draft Cabinet and Ministerial Ordinances," Kinyu Zaimu Kenkyukai, August 2007
Associate
Yushi Mochizuki
Yushi Mochizuki joined HCA Law Office in 2020 after practicing at law firms in Tokyo. His work spans a broad range of corporate legal matters, including M&A, business restructuring, litigation, shareholder derivative actions, and labor and employment compliance. He supports startups and established companies alike with practical, business-oriented legal solutions.
Main Practice Areas
- General Corporate
- Mergers & Acquisitions (M&A)
- Venture Legal Support
- Litigation / Dispute Resolution
- Labor & Employment Compliance
- Insolvency & Business Restructuring
Education & Professional Background
2013 | LL.B., Waseda University |
2015 | J.D., Waseda Law School |
2017–2020 | Associate, at a law firm (Tokyo) |
2020–Present | Associate, HCA Law Office |
Memberships
- Tokyo Bar Association
Associate
Nozomu Yoshimoto
Nozomu Yoshimoto joined HCA Law Office in 2021 following the completion of his legal training. He handles a range of corporate legal matters, including M&A, venture support, and commercial litigation, and provides practical advice tailored to clients at various stages of growth.
Main Practice Areas
- General Corporate
- Mergers & Acquisitions (M&A)
- Venture Legal Support
- Litigation / Dispute Resolution
Education & Professional Background
2017 | LL.B., Hokkaido University |
2019 | J.D., Hokkaido University Law School |
2021–Present | Associate, HCA Law Office |
Memberships
- Daini Tokyo Bar Association
Associate
Kosuke Nakamura
Kosuke Nakamura joined HCA Law Office in 2022 after gaining experience at a law firm in Nagoya. His practice focuses on general corporate matters, M&A, venture legal support, and litigation, offering practical legal solutions to clients in diverse industries.
Main Practice Areas
- General Corporate
- Mergers & Acquisitions (M&A)
- Venture Legal Support
- Litigation / Dispute Resolution
Education & Professional Background
2017 | LL.B., Hokkaido University |
2019 | J.D., Hokkaido University Law School |
2021 | Associate, at a law firm (Nagoya) |
2022–Present | Associate, HCA Law Office |
Memberships
- Daini Tokyo Bar Association
Associate
Keiichi Yumoto
Keiichi Yumoto joined HCA Law Office in 2025 after practicing at a law firm in Tokyo. He specializes in general corporate matters, M&A, venture legal support, and litigation, drawing on his extensive professional experience.
Main Practice Areas
- General Corporate
- Mergers & Acquisitions (M&A)
- Venture Legal Support
- Litigation / Dispute Resolution
Education & Professional Background
2017 | LL.B., Chuo University |
2019 | J.D., Chuo Law School |
2022–2025 | Associate, at a law firm (Tokyo) |
2025–Present | Associate, HCA Law Office |
Memberships
- Tokyo Bar Association
Associate
Tsutomu Nagai
Tsutomu Nagai joined HCA Law Office in 2025 after practicing at a law firm in Tokyo. He focuses on providing legal counsel in general corporate matters, M&A, venture legal support, and litigation, assisting clients with diverse legal challenges.
Main Practice Areas
- General Corporate
- Mergers & Acquisitions (M&A)
- Venture Legal Support
- Litigation / Dispute Resolution
Education & Professional Background
2020 | LL.B., Meiji University |
2022 | J.D., Keio University Law School |
2023–2025 | Associate, at a law firm (Tokyo) |
2025–Present | Associate, HCA Law Office |
Memberships
- Dai-Ichi Tokyo Bar Association