Timeline for September 2025

1

The Japan Meteorological Agency announces that the average temperature in summer 2025 (June to August) was 2.36° Celsius higher than the normal level (based on the 30-year average up to 2020). This makes it the hottest summer since records were first kept in 1898.

2

Suntory announces that its Chairman Niinami Takeshi resigned on September 1. Niinami was subject to a search of his house in August on suspicion that he had imported US supplements containing harmful ingredients derived from cannabis. On September 30, Niinami resigns as the chairman of Keizai Dōyūkai (Japan Association of Corporate Executives).

4

US President Donald Trump signs an executive order implementing a tariff agreement with Japan. This means the United States will lower its tariffs on Japanese vehicles and parts from 27.5% to 15%.

Singer Hashi Yukio, known for songs including “Itsu demo yume o” (Always Dreaming), dies at the age of 82.

5

Swimmer Narita Mayumi, who won 15 gold medals at the Paralympics and a total of 20 medals altogether, dies of cancer at the age of 55.

The “Queen of the Water” Narita Mayumi won seven gold medals and one bronze at the 2004 Paralympics in Athens. (© Jiji)

A tornado hits Makinohara and other parts of Shizuoka Prefecture as Tropical Storm Peipah passes through, causing extensive damage and injuring 89 people. On September 8, the Japan Meteorological Agency states that the wind reached speeds of 75 meters per second, making it one of the strongest ever recorded in Japan.

6

Prince Hisahito, the son of Crown Prince Fumihito and the nephew of Emperor Naruhito, has an official coming-of-age ceremony. It is the first coming-of-age ceremony for an imperial prince since that of his father 40 years ago.

Prince Hisahito wears a new kanmuri headpiece to show that he has come of age at the Kakan no Gi ceremony at the Imperial Palace on September 6, 2025. (© Jiji)

Tennis player Oda Tokito wins the US Open men’s wheelchair singles title for the first time, completing his career Golden Slam by winning all four of the major tournaments, as well as the Paralympics title.

Oda Tokito celebrates after winning the US Open men’s wheelchair singles title in New York on September 6, 2025. (© AFP/Jiji)

7

Prime Minister Ishiba Shigeru announces his resignation. There had been growing calls for him to step down following the Liberal Democratic Party’s poor performance in the July House of Councillors election.

The Hanshin Tigers win the Central League for the seventh time. It is the earliest in the season ever for a team to win the pennant either of Japan’s professional baseball leagues.

12

Nippon Life Insurance announces that its employees stole information on 604 occasions while on loan at other companies between May 2019 and February 2025.

13

The World Athletics Championships begin in Tokyo with 2,000 athletes from 200 countries. Katsuki Hayato wins a bronze medal in the men’s 35-kilometer walk on the opening day, which is one of two bronze medals for Japanese athletes during the competition.

16

The average land price rises by 1.5% year on year, for the fourth consecutive year of increases. Prices of residential land in areas outside the major cities remain steady, ending a 30-year decline.

19

The Bank of Japan decides at its policy meeting to sell exchange-traded funds that it acquired during its period of extraordinary monetary easing. This is another step toward normalization of its monetary policy.

The Japan Association for the 2025 World Exposition announces that the number of visitors to Expo 2025 Osaka Kansai topped 20 million on day 159, just under a month before it is due to end on October 13. As of September 27, the total reaches more than 22 million, overtaking the total for the 2005 Expo in Aichi Prefecture.

The government compiles a package of measures to promote anime, films, and other digital content in overseas markets.

21

Techno-pop group Perfume announces that it will go on hiatus at the end of 2025. The group made its debut in 2005, rising to fame with its 2007 single “Polyrhythm.”

22

The campaign period begins for the election of a new LDP leader to replace Ishiba Shigeru, the party’s current president. The five candidates (in alphabetical order) are Hayashi Yoshimasa, Kobayashi Takayuki, Koizumi Shinjirō, Motegi Toshimitsu, and Takaichi Sanae. Voting will take place on October 4.

Japan decides not to recognize Palestine as a state for the time being, following the United States, despite new recognition of Palestine by allies including Britain, Canada, and France.

25

The Japan International Cooperation Agency announces that it will scrap its “hometown” plan pairing Tanzania, Ghana, Nigeria, and Mozambique with four Japanese municipalities for international exchange. Misinformation, including a statement on a Nigerian government website that Japan would introduce special visas, led to the circulation of claims that the plan would lead to increased settlement of immigrants in Japan, bringing a wave of criticism.

27

Yoneda Satoshi wins the Besancon International Competition for Young Conductors. He is the first Japanese winner since Okisawa Nodoka in 2019.

Yoneda Satoshi acknowledges the acclaim of the crowd In Besancon on September 27, 2025. (© Jiji)

28

Ōnosato wins the autumn Grand Sumō Tournament, which is his first championship since becoming a yokozuna. In a playoff, he defeats Hōshōryū, who was also recently promoted to sumō’s top rank.

Ōnosato (right) forces Hōshōryū out of the ring in the decisive bout in Tokyo on September 28, 2025. (© Jiji)

30

Tanaka Masahiro of the Yomiuri Giants becomes the fourth pitcher to reach 200 career wins in Japanese and US professional baseball.

(Translated from Japanese: Banner photo: The five candidates for the Liberal Democratic Party presidential election. From left, Kobayashi Takayuki, Motegi Toshimitsu, Hayashi Yoshimasa, Takaichi Sanae, Koizumi Shinjirō. Picture taken at LDP headquarters in Tokyo on September 22, 2025. © Jiji.)