# 1921 in Japan

Events from the year 1921 in Japan. It corresponds to Taishō 10 (大正10年) in the Japanese calendar.

## Incumbents

* Emperor: Taishō
* Regent: Hirohito (from November 25)
* Prime Minister:
** Hara Takashi (until November 4)
** Takahashi Korekiyo (from November 13)

### Governors

* Aichi Prefecture: Shunji Miyao (until 18 April); Hikoji Kawaguchi (starting 18 April)
* Akita Prefecture: Ryoshin Nao
* Aomori Prefecture:
** until 9 March: Hidehiko Michioka
** 9 March-28 September: Shundo Kahei
** starting 28 September: Yujiro Ozaki
* Ehime Prefecture: Toshio Mawatari (until 27 May); Juunosuke Miyazaki (starting 27 May)
* Fukui Prefecture: Kohei Yuji (until 27 May); Josuke Shiraogawa (starting 27 May)
* Fukuoka Prefecture: Yasukouchi Asakichi
* Fukushima Prefecture: Miyata Mitsuo
* Gifu Prefecture: Kanokogi Kogoro (until 27 May); Manpei Ueda (starting 27 May)
* Gunma Prefecture: Muneyoshi Oshiba
* Hiroshima Prefecture: Raizo Wakabayashi (until 19 July); Ichiro Yoda (starting 19 July)
* Ibaraki Prefecture: Yuichiro Chikaraishi (until 27 May); Genjiro Moriya (starting 27 May)
* Iwate Prefecture: Takeo Kakinuma
* Kagawa Prefecture: Yoshibumi Satake
* Kochi Prefecture: Abe Yoshihiko
* Kumamoto Prefecture: Hikoji Kawaguchi (until 27 May); Sansuke Nakayama (starting 27 May)
* Kyoto Prefecture: Eitaro Mabuchi (until July); Raizo Wakabayashi (starting July)
* Mie Prefecture: Haruki Yamawaki
* Miyagi Prefecture: Mori Masataka (until 27 May); Yuichiro Chikaraishi (starting 27 May)
* Miyazaki Prefecture: Naomiki Hirose (until 3 July); Goro Sugiyama (starting 3 July)
* Nagano Prefecture: Tenta Akaboshi (until 27 May); Tadahiko Okada (starting 27 May)
* Niigata Prefecture: Ota Masahiro
* Okayama Prefecture: Masao Kishimoto
* Okinawa Prefecture: Sōsuke Kawagoe (until 27 May); Jyun Wada (starting 27 May)
* Saga Prefecture: Sawada Ushimaro (until 3 June); Tominaga (starting 3 June)
* Saitama Prefecture: Horiuchi Hidetaro
* Shiname Prefecture: Sanehide Takarabe
* Tochigi Prefecture: Hiroyoshi Hiratsuka
* Tokushima Prefecture: Rinpei Otsu (until month unknown)
* Tokyo: Hiroshi Abe (until 27 May); Katsuo Usami (starting 27 May)
* Toyama Prefecture: Higashizono Motomitsu (until 24 December); Shida Jisho (starting 24 December)
* Yamagata Prefecture: Ichiro Yoda (until 19 July); Morimoto Izumi (starting 19 July)
* Yamanashi Prefecture: Miki Nagano

## Events

* January 15 – Mitsubishi Electronics was separate section from Mitsubishi Shipbuildings (now Mitsubishi Heavy Industries) which was founded in Ōsone, Nagoya.
* January Unknown date – Komatsu Limited was founded, as predecessor name was Komatsu Ironworks.
* September – Sempill Mission sent by Britain to Japan, with the objective of helping the Imperial Japanese Navy develop its aeronaval forces.
* October 16 – Janome Sewing Machine founded.
* November 4 – Prime Minister Hara Takashi is assassinated at Tokyo Station.
* November 12 – Washington Naval Conference opens at Memorial Continental Hall Hall in downtown Washington DC.
* November 25 – Crown Prince Hirohito is made regent in place of his ailing father.
* December 13 – In the Four-Power Treaty on Insular Possessions, Japan, the United States, United Kingdom, and France agree to recognize the status quo in the Pacific.
* Termination of Anglo-Japanese Alliance.
* Ladies' Agreement
* Unknown date – Otsuka Pharmaceutical (大塚製薬) founded in Naruto, Shikoku Island.

## Births

* January 3 – Natsuko Kahara, actress (d. 1991)
* January 26 – Akio Morita, businessman and co-founder of Sony Corporation (d. 1999)
* February 9 – Junzo Shono, writer (d. 2009)
* February 11 – Edward Seidensticker, scholar, historian, and translator (d. 2007)
* February 14 – Toshiko Taira, textile artist (d. 2022)
* March 19 – Heitaro Nakajima, engineer (d. 2017)
* April 20 – Michiko Inukai, writer and philanthropist (d. 2017)
* December 20 – Kosuke Gomi, novelist (d. 1980)

## Deaths

* January 13 – Ijuin Gorō, admiral (b. 1852)
* June 19 – Nabeshima Naohiro, politician and former daimyō (b. 1846)
* September 28 – Yasuda Zenjirō, entrepreneur, founder of the Yasuda zaibatsu (b. 1838)
* November 4 – Hara Takashi, Prime Minister of Japan (b. 1856)
* November 5 – Yusuke Hashiba, archaeologist, historian and anthropologist (b. 1851)
* December 29 – Hayashi Yūzō, politician (b. 1842)