Locations already jockeying for the front-runner position to become a "backup" capital include Hokkaido, Osaka, and Fukuoka.
There they go again, looking for another construction boom in the land of earthquakes, tsunamis and nuclear accidents.
From Jiji Tsushin (2/8/2012):
Democratic Party of Japan to consider backing up of the capital functions
Democratic Party of Japan will hold the first meeting of "the working group for backing up the core functions of the capital" (headed by Sumio Mabuchi, former Minister of Land, Infrastructure and Transportation) on February 10. It is to prepare for the case of Tokyo devastated by an epicentral earthquake. The focus will be whether the group designates a location to temporarily move the function of the Prime Minister's Official Residence and the central government ministries. The group will submit the report to the government by the end of March.
The expert committee at the Ministry of Land, Infrastructure and Transportation started the discussion on backup functions of the capital last December, in light of the March 11, 2011 earthquake/tsunami. The committee says it won't specify the location [to which the functions will be moved], but heated campaigns to become a "backup" capital have already started among locations including Hokkaido, Osaka, and Fukuoka City.
Well, even after the Fukushima I Nuke Plant accident, they still do not (or cannot) say they should consider a potential nuclear disaster when planning a backup capital. If they do consider, there may be nowhere in Japan that's suitable.