Dōshūsei (道州制) is a proposal to organize Japan into one circuit of Hokkaido (dō) and several new states (shū) that are each a combination of several prefectures. The states and circuit are proposed to have greater regional autonomy, similar to the United Kingdom. It was first proposed by the Junichiro Koizumi administration, but has yet to materialize.
Most of the political parties in 2012 support this reform.
References
Dōshūsei Wikipedia(Text) CC BY-SA