OKC

What OKC does

OKC (大岡税務会計事務所 / 株式会社OKC) is a privately-held Japanese tax accounting and professional services firm headquartered in Kure City, Hiroshima Prefecture, at 〒737-0125 広島県呉市広本町一丁目6-23-201. The practice traces its origin to September 26, 1970, when the sole-proprietorship 大岡税務会計事務所 was established; the corporate entity 株式会社OKC was incorporated on September 12, 1977, giving the firm 48+ years of continuous operation under its current corporate form. The company is family-controlled, with Hiromi Ooka (大岡弘美) and Hiroyoshi Ooka (大岡弘欣) serving as Representative Directors, and operates with 12 staff (10 full-time, 1 part-time, 1 consultant) as of February 2026.

The firm delivers four core service lines: (1) Accounting Services (経理業務) — bookkeeping outsourcing, computer accounting setup support, payroll, trial balance, and financial statement preparation; (2) Tax Accountant Services (税理士業務) — corporate and individual tax filing, year-end adjustment, fixed asset tax filings, and inheritance/gift tax consultation; (3) Administrative Procedures Services (行政書士業務) — construction industry permit applications, other government filings, and corporate and medical corporation establishment consulting; and (4) Management Consulting Services (経営コンサルティング業務) — business planning, business succession, new business launch support, and risk management. Service delivery relies entirely on licensed professionals (four 税理士, two of whom also hold 行政書士 credentials) using standard PC-based accounting software; the firm has no proprietary technology platform, API, app, or AI capability.

OKC's revenue model is professional services fees earned through direct client engagement, with quote-based pricing and no publicly disclosed tiers. Go-to-market is direct-to-consumer via walk-in consultations at the Kure office, phone (0823-72-5522), and email ([email protected]), supplemented by referrals from existing clients and partner professionals. The firm serves small-to-medium local businesses and individual taxpayers across the Hiroshima region (Kure, Higashihiroshima, Hiroshima, Hatsukaichi, Mihara, Miyoshi, Aki-gun) and Shimonoseki in neighboring Yamaguchi Prefecture. There is no external equity investment, no parent company, no subsidiaries, and no disclosed revenue.

Name

OKC

Legal name

大岡税務会計事務所

Website

https://okc-h.com

Company type

Private

Founded year

1970

Operating status

Operating

Headcount range

11–50 employees

Short description

OKC is a privately-held Japanese tax accounting and consulting firm in Kure, Hiroshima, established 1970. It serves local small-to-medium businesses and individual taxpayers with accounting, tax filing, administrative scrivener, and management consulting services through 12 staff, including four licensed tax accountants.

Ownership category

akta.pro rank

Headquarters

HQ city

Kure

HQ country

Japan

HQ region

Asia

Offices1 record

Markets served

GTM type

B2B and B2C

Offering type

Services

Cost components

Personnel, Operations, Marketing or Sales, Technology or R&D

Revenue model

1. Professional Services Fees: Fees for accounting operations, tax filing, administrative document preparation, and management consulting services provided to businesses and individuals in the Hiroshima region.

Go-to-market motion1 record

Distribution channels1 record

Core offering

OKC (大岡税務会計事務所 / 株式会社OKC) is a Japan-based tax accounting and management consulting firm providing four core service lines: accounting operations (bookkeeping, payroll, financial statements), tax accountant services (corporate/individual tax filing, year-end adjustments, inheritance/gift tax planning), administrative scrivener services (construction permits, corporate and medical corporation establishment), and management consulting (business planning, business succession, risk management). Services are delivered directly to small and medium businesses and individual clients in the Hiroshima region.

Product overview

OKC (大岡税務会計事務所) operates as a tax accounting firm offering integrated professional services. The firm provides four core service lines: Accounting Services (経理業務), Tax Accountant Services (税理士業務), Administrative Procedures Services (行政管理業務), and Management Consulting Services (経営コンサルティング業務). These services are delivered through the parent company 株式会社 OKC and its associated 大岡税務会計事務所 office, serving clients across Hiroshima Prefecture and surrounding areas.

Differentiator

Problem solved

Functional benefit

Segments2 records

Ideal customer profiles2 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Scale indicators2 records

Recent moves4 records

Expansion highlights2 records

Broad incumbents

• TKC Corporation: TKC operates Japan's largest network of tax accountant and CPA member firms, offering accounting, tax, and consulting services nationally. It is broadly comparable to OKC in service scope but at vastly greater scale and with a national franchise and proprietary TKC cloud platform.
• Aoyama Sogo Accounting Firm (Aoyama Group): Aoyama is one of Japan's largest accounting and tax advisory groups, providing audit, tax, and consulting services to large corporates and SMBs. Comparable service mix (tax, accounting, advisory) but with national reach and significantly larger headcount than OKC.
• MJS (Mikuni & Co.): MJS provides accounting, tax, payroll, and consulting services to Japanese SMBs through a national network. Comparable in target customer (small/mid-sized businesses) and core offering (accounting + tax + advisory) to OKC, but with broader geographic coverage.
• TOMA Group (TOMA Consultants): TOMA is a Japanese tax-accounting and business consulting group serving SMBs and high-net-worth individuals with succession, tax, and management advisory. Closely comparable to OKC's stated menu (business succession, tax planning, management consulting), with greater scale and multi-office coverage.
• ASG Group (Asahi Tax Accountant Group): ASG is a Japanese tax accountant and consulting network serving SMBs nationwide with accounting, tax, and business succession services. Direct overlap with OKC's SMB-focused tax and management consulting service line.

Emerging players

• freee K.K. freee provides cloud-based accounting, payroll, HR, and tax-filing SaaS targeted at Japanese SMBs, automating tasks OKC currently performs manually (bookkeeping, payroll, year-end adjustments). It is a competitive substitute rather than a direct peer, but addresses the same SMB accounting buyer.
• Money Forward, Inc. Money Forward offers cloud accounting, payroll, expense, and tax software for Japanese SMBs and accountants, including an accountant-partner channel that competes with traditional firms like OKC for end-client relationships. Comparable buyer profile and overlapping product set with OKC's bookkeeping/payroll offerings.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat3 records

Key risks5 records

Key highlights6 records

Customer concentration

Revenue estimate

Valuation estimate

Number of profiles

Profiles2 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about OKC