Reina MizukaedeChief Information Officer

Personal correspondence

Renting the system, still owning the promise

Chief Information Officer Japan

Technology for a Shikoku securities firm whose median customer is sixty-eight years old.

My first employer kept its computer room on the third floor of an office block near Takamatsu port, and in April 1996 I joined it as a junior programmer. Akashiba Computing Centre ran overnight batch processing for credit cooperatives, agricultural cooperatives and two municipal payrolls. I wrote and maintained COBOL programs under a senior engineer who compared every change against the previous night's output totals. The most useful habit she gave me was to ask what a customer would see at nine o'clock if a job ran late. From 1998 I spent most of my time on year-2000 remediation, reading date logic written before I was born and testing it with the cooperatives' own clerks.

Our customers never chose our suppliers, our batch windows or our sign-in methods, yet each of those choices decides whether they can sell a holding on the morning they need to. I treat every system we rent, configure or switch off as a commitment the firm has made to someone at a counter in Kochi or a kitchen table in Imabari. Sales, compliance and operations own their decisions. My part is to make the limits of our technology plain before the morning they matter.

Customer assets in custody
¥1.12tn
186,000 active accounts at March 2026
Branches
27
Kagawa, Ehime, Tokushima, Kochi and Okayama
Annual technology budget
¥2.6bn
Including ¥1.4bn of shared back-office fees

A regional broker that rents its core systems still owns every promise those systems make to its customers.

I am executive officer and chief information officer of Ogiwatari Securities, a Takamatsu firm founded in 1921 that holds ¥1.12 trillion of customer assets across 186,000 active accounts. Our 27 branches serve Kagawa, Ehime, Tokushima, Kochi and Okayama, and the median account holder is sixty-eight. I lead 58 technology staff through four general managers, with about forty contractors and an annual budget of ¥2.6 billion. More than half of that budget pays for a shared back-office service that we use alongside 22 other securities firms. I report to the president and present system risk to our board; I am not a director.

I started in 1996 writing COBOL batch jobs for credit cooperatives at a Takamatsu computing centre. Card authorisation work in Matsuyama and seven years at an Osaka systems integrator showed me how financial systems fail, and how often a failure appears first at a counter rather than on a console. I came to Ogiwatari in 2013 to lead the move from our own mainframe onto the shared service, which went live over Golden Week in 2016. It removed most of our bespoke code, and it means our most important overnight processing now runs on someone else's machines.

This site describes three decisions taken inside that dependence. During a supplier batch failure, we accepted orders only from accounts whose positions we could still trust and held the rest until late morning. After the account takeovers that struck Japanese online brokerages in 2025, we made passkeys compulsory and moved thousands of customers to telephone ordering. Earlier, I asked the board to fund an inheritance case system before a customer app, and we missed the opening months of the new NISA as a result. Each choice cost somebody something, and I have tried to say who.

1,180 accounts waited so that nobody traded on stale positions

When the shared service could not post Monday's trades, we accepted orders from every account without activity that day and held the 1,180 that had traded or moved cash until 11:20. No settlement failed; 214 customers complained, and two took the matter to the industry's dispute-resolution service.

Passkeys became compulsory across 41,000 online accounts

From October 2025 we removed password-and-code sign-in with no SMS fallback. 3,400 customers moved to telephone ordering at online commission rates for a year, and 1,700 had online access suspended until they enrolled at a branch.

Inheritance transfers fell from 94 days to 41

The board funded a ¥410 million inheritance case system ahead of a customer app. Median transfer time fell to 41 days, but the app arrived only in March 2025, and we opened 9,800 new NISA accounts in 2024 against a plan of 16,000.

Current focus

I am renegotiating our shared-service contract, which runs to March 2028, so that the exit terms, the returned-data format and the 06:30 position file are each tested yearly rather than written once and assumed.

Conversations I welcome

I would consider one outside-director seat at a listed company in western Japan from April 2027, with about twenty-four days a year, subject to my president's consent and a review of the relationships set out on my readiness page.

The leadership record

Trusted with consequential decisions.

Formation

  • Bachelor of engineering in information scienceHanatsuge University · 1996
I argued against her that November morning, and I still think some of my held customers deserved better than a phone call at eleven. But nobody sold shares they no longer owned, and Reina came to the branch managers' meeting herself to explain why.
Tetsuo HagimuraHead of retail sales, Ogiwatari Securities
The full record ↗

Contact

I would consider one outside-director seat at a listed company in western Japan from April 2027, with about twenty-four days a year, subject to my president's consent and a review of the relationships set out on my readiness page.

  • Board appointments
Write to Reina Contact page