January 1 – A strong (magnitude 7.0), but very deep (370 km) earthquake shakes large parts of Eastern Japan at a JMA-intensity of 4. The quake with an epicenter about 500 km South of mainland Tokyo in the Pacific Ocean near Torishima, Tokyo doesn't cause any reported serious damage or injuries, but can be felt (intensity≥1) from Southern Hokkaidō to Chūgoku.
January 13 – In a cabinet reshuffle, prime minister Noda replaces five ministers, including two who had been subject of censure motions by the opposition dominated upper house in December 2011; Katsuya Okada becomes deputy prime minister.
late January and early February – At least 50 people die in heavy snow and record low temperatures across the country.
February 5 – Kyoto City mayoral election: In the traditional Communist stronghold, incumbent mayor Daisaku Kadokawa won re-election with support from the major parties against JCP-supported Kazuo Nakamura by 54 to 46 percent of the vote.
February 10: The central government sets up the reconstruction agency (fukkō-chō) to coordinate the reconstruction efforts after the Great East Japan Earthquake of 2011 with a central budget, replacing the previous reconstruction headquarters (fukkō taisaku honbu) at the Cabinet Secretariat. Tatsuo Hirano becomes reconstruction minister; Masaharu Nakagawa returns to the cabinet to take over some responsibilities from Katsuya Okada and Tatsuo Hirano.
February 29: Tokyo Skytree construction is completed.
May 22 - The Tokyo Skytree, which was completed on 29 February 2012, officially opened to the public.
June 5 – In a cabinet reshuffle, prime minister Noda replaces five ministers, including two who had been subject to censure by the opposition dominated upper house in April 2012; Satoshi Morimoto becomes the first non-parliamentarian defence minister.
October 1 – Prime minister Yoshihiko Noda reshuffles his cabinet for the third time; newly appointed justice minister Keishū Tanaka soon faces calls to resign over a report about an (illegal) political donation from a foreigner and contacts to Yakuza members.
October 21 – Niigata governor Hirohiko Izumida, supported by the major non-communist parties (DPJ, LDP, LF, Kōmeitō, SDP), is reelected for a third term against Communist challenger Shijio Hiwatashi and perennial Smile Party candidate Mac Akasaka.