Welcome to our office

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I have worked at both Big 4 and mid-sized tax firms, gaining extensive experience in international taxation, M&A, and corporate restructuring.
My background includes supporting startups with incorporation and payroll/social insurance procedures, assisting foreign companies entering the Japanese market, and providing tax advisory services for large-scale M&A and restructuring projects for various types of corporations.
Through these experiences, I’ve come to believe strongly in offering truly necessary services—tailored to each client’s stage and challenges—in a more approachable and collaborative way, as a trusted partner of each client.

At our office, we don’t offer one-size-fits-all solutions. Instead, we focus on flexible, personalized support for each client.
We strive to clarify what’s needed at each stage of your business journey, and to be a long-term partner in shaping your future.


Please feel free to reach out—we’re here to help.

Profile

2009 – 2015：Mid-sized tax firm in Japan

　I have provided tax and accounting services for both domestic and international corporations, as well as individual clients – including foreign nationals – at a mid-sized tax firm founded by several members with backgrounds at Arthur Andersen Tax Japan.

Key Service Experience

  • Preparation of tax returns, tax advisory, and tax audit support for corporations with annual revenues ranging from several million to several billion USD
  • Advisory and filing support related to tax treaties for cross-border transactions
  • Bookkeeping and reporting services for Special Purpose Companies (SPCs)
  • Bookkeeping and financial reporting for foreign-owned companies operating in Japan
  • Bookkeeping, payroll processing, and social insurance procedures support
  • Income tax return preparation for individuals, both Japanese and foreign nationals in Japan
  • Tax advisory for foreign investors regarding investments in Japan, etc.

2015－2023：PwC Tax Japan

　As a senior manager in financial service division of PwC Tax Japan, I provided tax compliance and tax advisory services to both Japanese and foreign financial institutions, such as PE funds, banks, securities firms, asset management companies and insurance companies, as well as non-financial corporates.

Key Service Experience

  • Tax due diligence, structuring and post-merger integration (PMI) for M&A of PE funds and financial institutions
  • Tax structuring and advisory for intra-group reorganizations within financial institutions
  • Tax structuring for outbound investments by Japanese entities
  • Preparation of tax returns, tax calculations, advisory services and tax audit support for domestic and international banks and securities
  • Tax compliance and advisory services for domestic and foreign insurance companies, including tax return preparation and tax audit support
  • Tax return preparation, tax calculations and advisory services for asset management companies and Japanese branches of foreign entities
  • Conducting tax training for client accounting and finance departments

2024 – 2025：RSM Tax Japan

　I provided tax compliance, tax advisory services as well as accounting services to foreign-owned companies at RSM.

Key Service Experience

  • Tax structuring for cross-border intra-group reorganizations within foreign corporate groups
  • Tax due diligence and structuring for M&A transactions of foreign entities
  • Preparation of tax memo regarding Japanese tax implications for foreign corporations providing e-services in Japan
  • Tax analysis for foreign organizations hosting events in Japan
  • Tax and accounting support for foreign corporations establishing entities in Japan, including incorporation assistance
  • Tax advisory for individual investors regarding investment structures
  • Preparation of tax returns and provision of tax advisory services for foreign-owned corporations
  • Income tax return preparation for foreign nationals in Japan
  • Tax advisory on Japanese withholding tax and treaty application for payments to non-residents, etc.

2025－2025：KPMG Tax Corporation

　As a senior manager in transaction advisory group of KPMG Tax Corporation, I provided tax advisory services to the clients including PE fund and investment bank.

Key Service Experience

  • Tax due diligence, structuring for M&A of PE fund and investment bank
  • Tax advisory services for outbound investments by Japanese entities
  • Coordinated cross-border tax due diligence processes and localized findings for Japanese clients, etc.

2025：Founded Omikawa Tax Office

Office Profile

Firm NameOmikawa Tax Office
AddressDF Building, 2-2-8 Minami-Aoyama, Minato-ku, Tokyo 107-0062, Japan
Tel+81 (80) 4858 4713
Representative Licensed Tax AccountantMasahiro Omikawa