Company history

TKC starts with a one-man practice. Demobilised from the army, Iizuka Takeshi opened an accounting office in Kanuma, Tochigi, in 1946; with almost no clients he spent the empty hours reading about how foreign firms worked, and his first customer — a woodworking shop that had seen the sign outside — arrived a year later. From that reading he imported a method unusual for a provincial practice: the junkai kansa, a monthly on-site audit of each client’s books rather than an annual reckoning. It earned him a reputation across northern Kanto, and by 1965 the office had ten staff and 150 client companies.

Then the state came for him. In 1962 the regional tax bureau issued corrective assessments against 36 of his clients on the grounds that he had coached them in tax evasion, and several of his staff were arrested. Iizuka denied it outright and sued. The fight ran eight years, the press called him a traitor, and the “Iizuka Incident” was debated in the Diet before every defendant was acquitted in November 1970. What he took from it was not vindication but a lesson about fragility: the independence of the accounting profession rested on very little.

A second shock arrived in the middle of it. Touring the United States in 1962, Iizuka saw computers arriving in accounting work and, more alarming, banks moving into the territory of accounting firms. He concluded the same would happen in Japan and that manual bookkeeping would carry the profession away with it. In October 1966 — still on trial — he set up Tochigi Prefecture Computing Center, later TKC, in Utsunomiya: a shared processing bureau accounting firms could use in common. Article 2 of the articles of incorporation names two purposes and no others, running a computing bureau “to defend the professional domain of accounting firms and open a way through their fate,” and running one to improve the efficiency of local government. Both pillars of today’s business are in that founding sentence.

From 1968 TKC rented computer time from Fujitsu by the hour and began taking in accounting work. The economics were brutal: $3 (¥1,000) a minute of machine time and 36 minutes to process a single company, so losses piled up in the early years. Shared processing only works with volume, and volume meant persuading a whole profession to come aboard.

The answer, in 1971, was the TKC National Federation — a non-profit association of accounting firms that wanted to audit with computers, sharing TKC’s services and the monthly on-site audit method built around them. Recruitment was miserable at first; fresh from the Iizuka Incident the name carried a stain, and a mailing of a thousand invitations to a seminar might produce a single attendee. But the seminars kept running, membership grew, and the association became something rarer than a customer list: a body of professionals whose own working method was TKC’s product.

With demand assured, the network went national. The Tokyo computing centre opened in August 1971, and between 1972 and 1976 subsidiaries followed in Osaka, Okayama, Tohoku, Nagoya, Kyushu and Saitama, reaching from Hokkaido to Okinawa. The company became Teikeishii in 1972 and TKC Corporation in December 1986. Renaming the “computing centres” as “information centres” in June 1987 marked the shift the business had already made — from selling machine time to managing accounting and tax information end to end.

TKC listed on the Second Section of the Tokyo Stock Exchange in July 1987, twenty-one years after founding. Asked what he would do with the money, the second-generation president Iizuka Masaharu said flatly that the company would not diversify. It was an unusual thing to say at a listing — the deliberate closing off of a growth route — and it held. Capital went into deepening two domains and vertically integrating everything they required: system development, information-centre operation, printing, member support. The company reached the TSE First Section in March 1996 still reporting three segments and no more.

What made the narrowness pay was that both customer groups were tied to statute. Every tax reform rebuilt the work of accounting firms; every administrative reform created computing demand in municipalities. In a structure where regulation delivers the work, speed and quality of compliance beat market exploration. TKC compounded that into a barrier: a case-law search service for member accountants from 1992, the consolidation of scattered regional centres into a handful of integrated ones, ISO 9001 in development, first private-sector qualification for connection to the government’s LGWAN network in 2003, privacy-mark certification, and in December 2008 an auditor’s report on the internal controls of its ASP services — a rare thing to be able to show a municipal official or a tax accountant, and hard for a latecomer to match.

The record ran to thirty consecutive years of higher revenue and profit through the year to September 2008, which closed at $529.4M (¥55bn) in revenue and $67.7M (¥7bn) in operating profit, all three segments profitable and the accounting-firm business supplying three-quarters of the total. Then, in October 2008, Iizuka Masaharu stepped down and Takada Junzo became the third president — the first head of TKC from outside the founding family, and the first move in a staged handover. Iizuka stayed on as chairman to hold the relationship with the Federation. Sumi Kazuyuki, also a career employee, succeeded in December 2011, arguing that TKC’s centralised processing model had anticipated the cloud rather than been overtaken by it.

Through the 2010s the accounting business moved to the cloud, with sustained investment against the invoice system and the electronic bookkeeping law, and the group absorbed the pieces it depended on — Skycom for electronic contracts and forms, later the printing subsidiary and the publishing arm. In October 2015 TKC became the first company in Japan to obtain third-party certification to ISO/IEC 27018 for personal-data protection in public clouds, extending the same instinct: turn a compliance standard into a moat.

In July 2017, marking the centenary of the founder’s birth, honorary chairman Iizuka Masaharu announced that he would give away one million of his personal shares over five years — free of charge, to members of the TKC National Federation. It is a peculiar capital structure and a deliberate one: the founding family’s holding migrates to the customers, so that shareholder and customer interests sit on the same base. In December 2019 Iizuka Masaki, the third generation and 44 at the time, became the fifth president. Against the fashionable view that automation would hollow out the tax profession, he argued the opposite — that assurance and management advice leave accounting firms far more room than routine filing ever did.

The other pillar became a government project. Japan’s standardisation of municipal systems set a hard migration deadline across the 164 authorities TKC serves; 68 had moved by the year to September 2025, and local-government revenue grew 35% in two years to $184.4M (¥28bn), alongside $352.8M (¥53bn) from accounting firms. The year to September 2025 marked a twelfth consecutive record for operating profit and an eleventh for net profit, an eleventh straight dividend increase, and — after the move to the TSE Prime Market in April 2022 and the exchange’s pressure on capital efficiency — a stated ROE target above 11% with $22.1M (¥3bn) of buybacks and $18.9M (¥3bn) of cancellations. A company that had returned value to its members in shares began returning cash to the market as well, without loosening its hold on the two businesses it has always had.