Prime Minister Naoto Kan, whose DPJ won a national landslide in August 2009, is under fire for his response to the earthquake, tsunami and nuclear plant breakdown, the Kyodo news agency reports.
In Tokyo, Gov. Shintaro Ishihara, 78, supported by the opposition Liberal Democratic Party, easily won a fourth term over a challenger backed by the DJP.
On the northern island of Hokkaido, LDP incumbent Harumi Takahashi was far ahead. Other LDP governors were not even challenged by the DJP.
The Liberal Democrats also were winning the mayoral election in Hiroshima, although losing in Sapporo.
The DPJ also lost ground in the election for the upper House of Councillors last July, which was seen as a referendum on its rule. Pressure was mounting for Kan to resign before the March 11 earthquake.