a proven tool for growth
and innovation

Corporate Japan is in dire need of increased diversity. In July 2020, a mere 6% of Japanese corporate board members were women. The Japanese Government’s Fifth Basic Plan for Gender Equality calls for directors and statutory auditors of companies listed on the First Section of the Tokyo Stock Exchange to be at least 12% women by 2022. Japan’s primary business federation, the Keidanren, has called for 30% female representation among board members and corporate executive officers by 2030.
OnBoard’s mission is to help corporate Japan achieve these diversification goals in an effective and value-generating manner, allowing Japanese industry to benefit from diverse perspectives and experiences. Diversity, in all forms, is a key driver in building corporate value and embracing innovation.

Our Services


Our experienced lecturers provide intensive training in areas such as law and accounting, and other practical skills necessary for successful service on corporate boards. Our clients are directors, statutory auditors and candidates for such positions. We further offer networking opportunities with lecturers and other participants. We also introduce suitable companies to participants after successful completion of our training programs. In addition, we offer seminars on corporate governance for a more general audience from time to time.

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We introduce experienced, talented and diverse candidates to our corporate clients for roles as directors and statutory auditors. Our candidates include lawyers, accountants and corporate executives. We use a skill matrix matching method to find the best human capital for the needs of our corporate clients. As our co-founders are both attorneys, we have a particular strength in procuring talent from the legal profession. We can also provide in-house trainings for director and officer candidates and consulting services to promote female directors and managers.

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Upcoming Seminar

Ask Directors and Audit & Supervisory
Board Members
- Practical Practices and
Secrets - (Japanese Only)

Date July 2023 – February 2024
Format Online Webinar
Language Japanese

Our Team

越 直美

Naomi Koshi

Co-Founder and CEO

Naomi Koshi is a lawyer and former two-term mayor of Otsu City, the capital of Shiga Prefecture in Japan.

From 2002 to 2011, Naomi practiced corporate law at Nishimura & Asahi in Tokyo and Debevoise & Plimpton in New York. From 2010 to 2011, Naomi was a Visiting Fellow at the Center on Japanese Economy and Business at Columbia Business School in New York, researching comparative corporate governance matters.

In 2012, Naomi was elected mayor of Otsu City, a prefectural capital with over 340,000 residents. Naomi won reelection in 2016, serving a total of eight years until her second term ended in 2020. Naomi was the youngest female mayor elected in Japan’s history, winning office at a time when only 3% of mayors in Japan were women. As mayor, Naomi fought to expand opportunities for Japanese women, especially through improving Otsu’s childcare system.

Naomi is admitted to practice law in Japan, New York and California and is now a partner of a large law firm in Tokyo.Naomi focuses her legal practice on cross-border M&A and start-ups, and she continues to write and speak on issues of gender equality. Naomi also serves as an outside director at both V-Cube, Inc. and SoftBank Corp.

Naomi was selected as a Young Global Leader by the World Economic Forum in 2015 and was named an OECD Champion Mayor for Inclusive Growth. She holds multiple degrees from Hokkaido University, and an LL.M. from Harvard Law School.

松澤 香

Kaoru Matsuzawa

Co-Founder and CEO

Kaoru Matsuzawa is a corporate lawyer with deep experience in public policy.

From 2002-2017, Kaoru practiced law at Mori Hamada & Matsumoto, after which she started an independent legal practice. In 2019, Kaoru joined several other lawyers to co-found a new Tokyo-based law firm that has already grown to more than 80 attorneys.

Throughout her career, Kaoru has focused on corporate law matters, including M&A and start-ups, as well as public policy and governance reform in both the public and private sectors. In 2011 and 2012, Kaoru managed an independent investigation commission of the Japanese Diet. Since then, Kaoru has held numerous public policy advisory and committee positions in both government and non-governmental organizations. In these positions, Kaoru has a track record of advocating for progressive reform and gender equality. In 2023, Kaoru was elected as an executive director (Governance Innovation) of Tokyo Medical and Dental University (TMDU).

Kaoru also serves on several start-up companies preparing for IPO corporate boards and publicly traded company. Kaoru has been an outside director and member of the audit and supervisory committees for SENSYN ROBOTICS, Inc. and MedicalNote, Inc. since 2020, a statutory auditor for ANDPAD Inc. and an outside director for Plaid Inc. since 2022. Kaoru holds an LL.B. from Keio University and an LL.M. from Harvard Law School and is admitted to practice law in Japan and New York. Since 2021, Kaoru has been listed in The Best Lawyers in Japan (Corporate Governance and Compliance Practice).

Company Information

Company Name:
OnBoard K.K.

Otemachi Office Address:
East Tower 4th Floor,
Otemachi First Square
1-5-1 Otemachi, Chiyoda-ku
Tokyo 100-0004 Japan

Toranomon Office Address:
CIC Tokyo
Toranomon Hills Business Tower 15th Floor,
1-17-1 Toranomon, Minato-ku
Tokyo 105-6415 Japan