Inflation (CPI) during each mayor's tenure
17 mayors, ranked by how the inflation (CPI) changed from their first day in office, next to the prefecture over the same months. Politare shows what happened during a tenure; it does not claim the office-holder caused it.
| # | Mayor | City | In office | Total | vs prefecture | Per year | Chart |
|---|---|---|---|---|---|---|---|
| 1 | Kibo Yuriko Koike | Tokyo | 2 Aug 2016 – now | +3.1 pp Jul 2016 → Sep 2026 | +0.5 pp prefecture +2.6 pp | +0.3 pp/yr | |
| 2 | Ishin Ichirō Matsui | Osaka | 8 Apr 2019 – 1 Apr 2023 | +3.1 pp Mar 2019 → Mar 2023 | +0.4 pp prefecture +2.7 pp | +0.8 pp/yr | |
| 3 | N Emiko Okuyama | Sendai | 22 Aug 2009 – 22 Aug 2017 | +3.0 pp Jul 2009 → Jul 2017 | +0.4 pp prefecture +2.6 pp | +0.4 pp/yr | |
| 4 | LDP Seishi Kōyama | Kumamoto | 3 Dec 2002 – 3 Dec 2014 | +2.9 pp Nov 2002 → Nov 2014 | +0.1 pp prefecture +2.8 pp | +0.2 pp/yr | |
| 5 | N Akira Shinoda | Niigata | 18 Nov 2002 – 18 Nov 2018 | +2.8 pp Oct 2002 → Oct 2018 | +0.5 pp prefecture +2.3 pp | +0.2 pp/yr | |
| 6 | Ind Katsuhiro Akimoto | Sapporo | 2 May 2015 – now | +2.7 pp Apr 2015 → Sep 2026 | +1.1 pp prefecture +1.6 pp | +0.2 pp/yr | |
| 7 | Ind Sōichirō Takashima | Fukuoka | 7 Dec 2010 – now | +2.4 pp Nov 2010 → Sep 2026 | +0.3 pp prefecture +2.1 pp | +0.2 pp/yr | |
| 8 | N Kazumi Matsui | Hiroshima | 12 Apr 2011 – now | +2.2 pp Mar 2011 → Sep 2026 | −0.5 pp prefecture +2.7 pp | +0.1 pp/yr | |
| 9 | O Takashi Kawamura | Nagoya | 28 Apr 2009 – 25 Nov 2024 | +2.2 pp Mar 2009 → Oct 2024 | −0.4 pp prefecture +2.6 pp | +0.1 pp/yr | |
| 10 | LDP Hayato Shimizu | Saitama | 27 May 2009 – now | +2.2 pp Apr 2009 → Sep 2026 | −0.1 pp prefecture +2.3 pp | +0.1 pp/yr |
Showing 10 of 43 tenures.
Sorted by total, highest first. Every row is indexed to the last month complete before the first day in office ("from" marks a start that had to move because that period had no data, or because the period cut it); the prefecture is measured over the same months. Levels are per cent changes, rates are differences in pp; "per year" compounds levels and divides rates. Tenures with under 12 months, or under three observations, are left out. % change on a year earlier · Statistics Bureau of Japan consumer price index via e-Stat (0003427113), all items, 2020 base, the city as a prefectural capital · city data · as of Sep 2026.