This article lists events in 2011 in Japan.
Incumbents
Emperor – Akihito
Prime Minister – Naoto Kan (D-Tokyo) until September 2, Yoshihiko Noda (D–Chiba) Chief Cabinet Secretary: Yoshito Sengoku until January 14, Yukio Edano until September 2, Osamu Fujimura Chief Justice of the Supreme Court: Hironobu Takesaki President of the House of Representatives: Takahiro Yokomichi (D–Hokkaidō) President of the House of Councillors: Takeo Nishioka (D–proportional) until November 5, Kenji Hirata (D–Gifu) from November 14 Diet sessions: 177th (regular, January 24 to August 31), 178th (extraordinary, September 13 to September 30), 179th (extraordinary, October 20 to December 9)
Governors
Aichi Prefecture: Masaaki Kanda (until 15 February); Hideaki Omura (starting 15 February) Akita Prefecture: Norihisa Satake Aomori Prefecture: Shingo Mimura Chiba Prefecture: Kensaku Morita Ehime Prefecture: Tokihiro Nakamura Fukui Prefecture: Issei Nishikawa Fukuoka Prefecture: Wataru Asō (until 22 April); Hiroshi Ogawa (starting 23 April) Fukushima Prefecture: Yūhei Satō Gifu Prefecture: Hajime Furuta Gunma Prefecture: Masaaki Osawa Hiroshima Prefecture: Hidehiko Yuzaki Hokkaido: Harumi Takahashi Hyogo Prefecture: Toshizō Ido Ibaraki Prefecture: Masaru Hashimoto Ishikawa Prefecture: Masanori Tanimoto Iwate Prefecture: Takuya Tasso Kagawa Prefecture: Keizō Hamada Kagoshima Prefecture: Satoshi Mitazono Kanagawa Prefecture: Shigefumi Matsuzawa (until 22 April); Yuji Kuroiwa (starting 23 April) Kochi Prefecture: Masanao Ozaki Kumamoto Prefecture: Ikuo Kabashima Kyoto Prefecture: Keiji Yamada Mie Prefecture: Akihiko Noro (until 20 April); Eikei Suzuki (starting 21 April) Miyagi Prefecture: Yoshihiro Murai Miyazaki Prefecture: Hideo Higashikokubaru (until 20 January); Shunji Kōno (starting 20 January) Nagano Prefecture: Shuichi Abe Nagasaki Prefecture: Hōdō Nakamura Nara Prefecture: Shōgo Arai Niigata Prefecture: Hirohiko Izumida Oita Prefecture: Katsusada Hirose Okayama Prefecture: Masahiro Ishii Okinawa Prefecture: Hirokazu Nakaima Osaka Prefecture: until 31 October: Tōru Hashimoto 31 October-28 November: Yasuyuki Ogawa starting 20 November: Ichirō Matsui Saga Prefecture: Yasushi Furukawa Saitama Prefecture: Kiyoshi Ueda Shiga Prefecture: Yukiko Kada Shiname Prefecture: Zenbe Mizoguchi Shizuoka Prefecture: Heita Kawakatsu Tochigi Prefecture: Tomikazu Fukuda Tokushima Prefecture: Kamon Iizumi Tokyo: Shintarō Ishihara Tottori Prefecture: Shinji Hirai Toyama Prefecture: Takakazu Ishii Wakayama Prefecture: Yoshinobu Nisaka Yamagata Prefecture: Mieko Yoshimura Yamaguchi Prefecture: Sekinari Nii Yamanashi Prefecture: Shōmei Yokouchi
Events
January
January 14 – Prime Minister of Japan Naoto Kan reshuffles his Cabinet. January 22 – An unmanned Japanese H-II Transfer Vehicle HTV-2 Resupply craft was launched atop the H-IIB rocket on a mission to deliver cargo to the International Space Station. January 26 – Shinmoedake volcano erupts in Shinmoedake and the surrounding areas, continuing until no earlier than March 10, in southern Kyushu Island.
February
February 6 – The Japan Sumo Association cancels the Spring Grand Sumo Tournament in light of a match fixing scandal, the first time the event has been canceled since 1946. February 26 – Nintendo's first 3D portable game console "Nintendo 3DS" is released in Japan.
March
March 7 – Seiji Maehara resigns as Foreign Minister of Japan after becoming involved in an illegal political donation scandal. March 9 – Takeaki Matsumoto is sworn in as the Foreign Minister of Japan, replacing Seiji Maehara who resigned following a political donations scandal. March 11 – A 8.9-magnitude earthquake hits offshore of Japan's Miyagi prefecture, resulting in tsunami waves as high as 10 metres, causing an accident at Fukushima I Nuclear Power Plant March 12 – Kyushu Shinkansen opens between Yatsushiro and Hakata of Fukuoka, with the start of direct high-speed train between Osaka to Kagoshima. March 23 – Tokyo tap water became contaminated by radiation due to the Fukushima I nuclear accidents. March 23 – The Grand Bench of the Supreme Court rules that voting weight disparity in the 2009 general election for the House of Representatives was in an unconstitutional state. March 25 – Vegetables grown in Tokyo were contaminated by radiation. March 31 – The Grand Prince Hotel Akasaka was due to be closed on this date, but remained open through June 2011 to house people displaced by the earthquake, tsunami, and nuclear alert.