Yuriko Koike

From 2017, Koike stopped sending the message of condolence that her predecessors had addressed to the ceremony commemorating Koreans killed during the violence following the Great Kantō Earthquake of 1923. Historians and associations denounced this break as trivialising the massacre.

State of the evidence

Annual decision and recurring criticism documented

Legal status — source text

No legal proceedings

Attribution

Direct personal responsibility as Governor

The Jingu Gaien redevelopment project involves rebuilding stadiums, erecting large buildings and removing or transplanting numerous trees. Associations, experts and residents denounced the loss of landscape heritage and criticised the environmental assessment.

State of the evidence

Approved project and opposition documented

Legal status — source text

Litigation and administrative proceedings; no personal criminal wrongdoing established

Attribution

Political responsibility as Governor supporting the metropolitan plan

Journalists, authors and former associates have maintained that Koike did not actually obtain the university degree she claims to hold. In 2024, a former associate also claimed to have participated in an operation intended to obtain a public statement from Cairo University before the 2020 election.

State of the evidence

Public allegations and complaints documented, categorically denied

Legal status — source text

No judgment establishing falsification as of 22 August 2026

Attribution

Personal responsibility alleged; evidence contested

Following Koike's re-election in July 2024, an election challenge cited, among other matters, her Cairo degree claim, the alleged involvement of mayors in requesting her candidacy and possible use of her position as Governor during the campaign. The metropolitan election commission's official decision examined these grievances.

State of the evidence

Grievances filed in an official election challenge and subsequently rejected

Legal status — source text

Metropolitan election commission rejected the objection; no annulment or conviction

Attribution

Personal responsibility alleged but not established

Koike supported holding the postponed Olympics in summer 2021 while Tokyo was experiencing COVID-19 waves and polls showed a strong preference for cancellation or another postponement. The Games eventually took place with almost no local spectators.

State of the evidence

Decision to proceed with Games, restrictions and public opposition documented

Legal status — source text

No legal proceedings

Attribution

Political responsibility as Governor of the host city, shared with the government, IOC and local organising committee

Shortly after her election, Koike postponed the transfer of Tsukiji market to Toyosu due to concerns about soil contamination and the absence of the promised layer of clean soil. The delay caused additional costs and prolonged uncertainty for traders.

State of the evidence

Postponement, contamination problems and additional costs documented

Legal status — source text

No personal criminal wrongdoing established

Attribution

Direct political responsibility as Governor

During the formation of the Party of Hope, Koike declared that she would "exclude" Democratic Party candidates who did not share her political positions, notably on security and the Constitution. The word "exclusion" became emblematic of the opposition's split and the new party's disappointing campaign.

State of the evidence

Statement, exclusions and election result documented

Legal status — source text

No legal proceedings

Attribution

Direct political responsibility as party founder and leader