Grant Thornton Taiyo LLC (太陽有限責任監査法人)

Wiki route

This entry sits under financial-regulators INDEX. Read it alongside Ey Shinnihon, Deloitte Touche Tohmatsu LLC (Deloitte Touche Tohmatsu), Kpmg Azsa, PwC Japan LLC (formerly PwC Arata) for the Big 4 comparison, and Financial licenses for the regulatory boundary of the Certified Public Accountants Act / audit quality control. The CPAAOB oversight context falls within the remit of FSA Supervision Bureau and Strategy Development and Management Bureau (FSA Strategy Development and Management Bureau).

1. Firm overview

• Legal name: Grant Thornton Taiyo LLC (limited-liability audit corporation) ^•
• English name: Grant Thornton Taiyo LLC ^•
• Corporate form: limited-liability audit corporation ^•
• Headquarters: Akasaka, Minato-ku, Tokyo ^•
• Member network: Grant Thornton International Limited (headquartered in London) ^•
• Group entities:
  • Grant Thornton Taiyo Tax Corporation
  • Grant Thornton Taiyo Advisors Co., Ltd. (FAS)
  • Grant Thornton Taiyo Risk Advisory Co., Ltd. ^•

2. History

IPO-preparation support (greatest strength) ^•

• Audits of companies preparing to list on the TSE Growth market / Standard market
• A major recipient of mid-tier listings where the Big 4 are thin

VASP / crypto-assets ^•

• Strength in financial-statement audits / segregation-of-customer-assets audits of mid-tier VASPs
• Handles cross-border crypto-asset engagements via the Grant Thornton global network
• As mentioned in Japan crypto audit-firm landscape — Big4 + Grant Thornton Taiyo + BDO Sanyu crypto-practice comparison, a representative quasi-major firm alongside the Big 4
• Compliant with the JICPA industry-specific committee practical guidelines 第 61 号 ^•

4. Major listed-FG client relationships (public basis)

Grant Thornton Taiyo has strengths in audits of mid-tier listed companies, IPO-preparation companies, and VASPs, but because the auditor of any individual company changes over time, this entry does not enumerate specific client names without a verifiable primary source. The latest information should be checked as needed in the “status of the auditor” section of each company’s securities report on EDINET.

5. Regulation / oversight

• Governing law: Certified Public Accountants Act ^•
• Registration: Japanese Institute of Certified Public Accountants (JICPA) ^•
• Oversight: the FSA’s Certified Public Accountants and Auditing Oversight Board (CPAAOB) conducts quality-control reviews / inspections ^•
• Quasi-major bracket: the CPAAOB categorizes audit firms into “major,” “quasi-major,” and “small-and-medium” to formulate inspection plans. Taiyo is positioned in the quasi-major bracket ^•

Disciplinary history

• 2023-12-26 FSA administrative disposition: on the grounds of false attestation in the financial-document audit of D.D.S., Inc. (the 2017-12 period through the 2022 1 -th quarter), the following were issued against Grant Thornton Taiyo LLC
  • Business-suspension order: suspension of business relating to the conclusion of new contracts for 3 months (2024-01-01 to 2024-03-31; the renewal of existing contracts and IPO-related matters were excluded)
  • Business-improvement order: improvement of audit execution / review structure / personnel management / quality control (submission of an improvement plan 2024-01-31)
  • The engagement-quality-review partner 1 名 was prohibited from involvement in review work for 3 months
  • The engagement CPAs 2 名 were each suspended from business for 6 months (2024-01-01 to 2024-06-30)
• 2024-02-29 surcharge-payment order: for the false attestation of financial documents (Article 34 -21 , paragraph 2 of the Certified Public Accountants Act 第 2 号), a surcharge of 95,950,000 円 (payment deadline 2024-04-30)

6. Competitive landscape

Sources: ^[This comparison is a FinWiki analytical grouping based on public firm descriptions, not an official market-share ranking: Grant Thornton Taiyo https://www.grantthornton.jp/about/firm/; BDO Sanyu https://www.bdo.or.jp/firm/; JICPA https://jicpa.or.jp/; CPAAOB https://www.fsa.go.jp/cpaaob/.]

Related

• ey-shinnihon (Big 4 peer comparison)
• deloitte-touche-tohmatsu (Big 4 peer comparison)
• kpmg-azsa (Big 4 peer comparison)
• pwc-aarata (Big 4 peer comparison)
• sbi-hd (related-client domain of mid-tier independent FGs — illustrative)
• INDEX (Certified Public Accountants Act / audit system)
• fsa-supervision-bureau (CPAAOB oversight context)
• japan-crypto-audit-firm-landscape (crypto-audit cross-domain)

Sources

• Grant Thornton Taiyo official: https://www.grantthornton.jp/
• Grant Thornton Taiyo firm information: https://www.grantthornton.jp/about/firm/
• Japanese Institute of Certified Public Accountants (JICPA): https://jicpa.or.jp/
• FSA Certified Public Accountants and Auditing Oversight Board (CPAAOB): https://www.fsa.go.jp/cpaaob/
• EDINET: https://disclosure2.edinet-fsa.go.jp/
• FSA, on disciplinary dispositions etc. of audit firms and certified public accountants (Grant Thornton Taiyo LLC, 2023-12-26): https://www.fsa.go.jp/news/r5/sonota/20231226-3/20231226.html
• FSA, on the decision of a surcharge-payment order (Grant Thornton Taiyo LLC, 2024-02-29): https://www.fsa.go.jp/news/r5/shouken/20240228.html

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[!info] Verification status confidence: likely (v1.0 based on public sources, 2026-05-24). The positioning as a quasi-major / mid-tier audit firm, Grant Thornton global membership, and the CPAAOB categorization are highly reliable on a public basis. The auditor of any specific client should be confirmed as needed against EDINET primary materials.