Tadashi MizukuraChief Data Officer

Tadashi Mizukura · Chief Data Officer · Japan

A career spent asking what the record knew, and when.

Chief Data Officer

Soravane Assurance

Sector
Property and casualty insurance
Ownership
Private insurer; founder holding company 54%, institutional investors 46%
Company scale
JPY 198 billion company gross written premium in FY 2025–26
Employees
5700 company employees at October 2026
Geography
Japan; headquarters in Tokyo
Reporting to
Chief Executive Officer
Team
124 data colleagues through seven direct reports at October 2026
Financial scope
JPY 1.86 billion delegated FY 2026–27 function expense; underwriting, claims, actuarial, finance and technology authority remain separate

Mandate

Retain the sequence and limits of information used to assess insurance decisions.

Outcomes

  • Withheld the original 2023 first-notice evaluation claim while reconstructing historically eligible inputs.
  • Preserved effective-date and recorded-date views in the 2021 policy-history work.
  • Kept the 2025 completed-claims median distinct from an age distribution of cases still open.

Decisions in context

The CDO remit lets me examine how evidence moves between functions without assuming ownership of every decision it supports. A first-notice evaluation, a policy-version history and a claims-duration account require different kinds of temporal explanation. I want the team to describe those differences before choosing a common technical treatment. My function expense funds data work, while professional and operating colleagues retain their own authority. Executive presentations to the board began with this appointment; I have no statutory director seat in the invented record. The company’s premium and workforce provide context rather than a personal management claim. This period has made me more willing to withdraw a persuasive analytical conclusion when the historical input basis is wrong, and more attentive to the people or cases a concise report leaves outside its visible population.

Reason for the move

Appointed CDO after insurance-data leadership; current role.

Director of insurance data

Soravane Assurance

Sector
Insurance data and analytical information
Ownership
Private property and casualty insurer
Company scale
JPY 146 billion company gross written premium in FY 2017–18
Employees
4400 company employees in FY 2017–18
Geography
Japan; data leadership based in Tokyo
Reporting to
Executive responsible for information and operations
Team
68 data colleagues through five direct reports in FY 2017–18
Financial scope
JPY 920 million annual function expense in FY 2017–18; no underwriting or reserving mandate

Mandate

Keep source precision and interpretation visible as information crosses insurance functions.

Outcomes

  • Separated building-level, postcode-level and unresolved classifications in the 2016 property-location account.
  • Retained 1200 unresolved entries as unknown instead of assigning unsupported precision.
  • Completed JPY 160 million review and reporting work without claiming a hazard or insured-loss result.

Decisions in context

This appointment widened my attention beyond claims events to the evidence used across insurance analysis. The property map was a useful example of the problem: an interface could make records look equally precise even when their underlying classifications differed. I wanted the data to retain that difference when reused, so that the specialist asking a location-dependent question could assess whether the source was fit for it. That required cooperation with colleagues who preferred a simpler presentation. My task was to explain why visible uncertainty improved the account rather than merely make a technical objection. The director title was an employment title. The role did not make me a statutory director or transfer responsibility for underwriting and reserves. Its wider institutional perspective prepared me to lead the data function while remaining clear about the authority that sat elsewhere.

Reason for the move

Advanced to CDO as the remit expanded into institution-wide data evidence and executive reporting.

Head of claims information

Soravane Assurance

Sector
Claims operating information for property and casualty insurance
Ownership
Private founder-led insurer
Company scale
JPY 82 billion company gross written premium in FY 2010–11
Employees
2900 company employees in FY 2010–11
Geography
Japan; claims-information team based in Tokyo
Reporting to
Director responsible for insurance information
Team
31 information colleagues through four direct reports in FY 2010–11
Financial scope
JPY 290 million annual function expense in FY 2010–11; claims decisions and payments separately authorised

Mandate

Maintain a claims account that distinguishes recorded events from conclusions about final outcomes.

Outcomes

  • Accepted responsibility for the 2007 final-resolution label attached to 7800 closure events.
  • Retained 260 subsequent reopenings within the ninety-day observation alongside the original closures.
  • Introduced status-at-cutoff reporting through JPY 48 million correction work.

Decisions in context

Moving inside the insurer gave me continuing responsibility for definitions that an analytical assignment might previously have left behind. The closure report showed how that responsibility could be mishandled. I approved a stronger interpretation than the operating event justified because I wanted a concise management measure. Kenji Aritsune’s challenge required me to separate the recorded closure from the later status and explain why my original wording was wrong. The correction preserved the event history rather than erase the cases that complicated it. I did not direct claims decisions or decide whether a reopening was justified; those responsibilities remained with claims colleagues. What changed was the account through which their work was described. This period taught me that an executive can overstate evidence without changing a single source value, simply by attaching a conclusion that the observation cannot support.

Reason for the move

Promoted into wider insurance-data responsibility after leading recurring claims information.

Engagement Lead

Kiyoremi Analytics

Sector
Statistical research and analytical advisory work
Ownership
Private analytical firm
Company scale
JPY 2.4 billion company fee revenue in 2003
Employees
130 company employees in 2003
Geography
Japan; insurance and institutional research assignments
Reporting to
Director of analytical delivery
Team
17 assignment colleagues through three direct reports in 2003
Financial scope
JPY 84 million annual delivery expense in 2003; client operating authority retained by clients

Mandate

Lead research that explains how an assembled record differs from the evidence available during the underlying event.

Outcomes

  • Required the analytical question to state the observation point relevant to the decision.
  • Explained the distinction between eventual file contents and historically available information.
  • Sought an insurer role to maintain the account after delivery of the original analysis.

Decisions in context

Leading assignments meant helping a client understand a result without requiring them to inspect every field. I found that the explanation of time was often shortened first. A dataset assembled at the end of a process could be described as historical evidence without saying which parts had arrived later. I wanted that qualification to survive the handover into management use. My team and delivery expense supported the research; the client retained decisions about insurance operations. Over time I became interested in the maintenance of definitions after an assignment ended. The move to Soravane was a way to accept that longer responsibility. It would expose my own reporting choices to repeated use and challenge, rather than let a well-explained final presentation stand as the last account of whether the work remained intelligible.

Reason for the move

Joined Soravane to take continuing responsibility for claims information within the institution using it.

Statistical Analyst

Kiyoremi Analytics

Sector
Applied statistical analysis
Ownership
Private research and advisory company
Company scale
JPY 720 million company fee revenue in 1996
Employees
48 company employees in 1996
Geography
Japan; analytical work delivered from Tokyo
Reporting to
Engagement lead
Team
Individual contributor in an eight-person analytical group
Financial scope
No independent expense delegation or line-management responsibility

Mandate

Understand the sequence through which institutional records become available for analysis.

Outcomes

  • Examined which stage of a process each source field described.
  • Distinguished the completeness of an extract from the completeness of knowledge at an earlier moment.
  • Developed an interest in the interpretation of retrospective insurance evidence.

Decisions in context

I began after completing applied statistics in March 1990. The work involved understanding the record before selecting the calculation: why a field existed, when it had been entered and whether it described the state of a process or a later account of its outcome. I was learning under an engagement lead, with neither people-management authority nor an independent spending mandate. The company figures for this period belong to a small research business and should not be read through the scale of my later insurer role. What carried forward was curiosity about the chronology hidden inside a completed file. It was a useful foundation, though it did not prevent my later closure-reporting mistake. The career includes that inconsistency because a principle learned early becomes more meaningful when the record also shows where I failed to apply it.

Reason for the move

Promoted to engagement leadership after developing analytical and client-explanation experience.

What I am looking for next

I would like my next contribution to involve an institution that needs to question the apparent certainty of its own retrospective evidence. An insurance board may be shown a completed-case measure, a historical evaluation or a location analysis whose limitations are hard to see in the summary. I could help colleagues identify the question that remains unanswered and ask management for an account that preserves the relevant history. That contribution would be made alongside, and with respect for, professional and operating expertise.

A first statutory appointment would require preparation beyond my executive presentations. Twenty-six days a year would be a provisional indication, subject to employer agreement, induction, committee work and periods of heightened demand. I would disclose insurance, supplier and advisory relationships before the institution assessed fit and independence. This fictional chronology records no existing directorship. A real next chapter would need verified evidence, permission to publish and a willingness to learn the responsibilities of the particular board rather than assume that an earlier data problem provides the answer to its current circumstances.