The government-backed pro-nuclear frontrunner in Tokyo's gubernatorial election has won the vote, major media reported, with two anti-nuclear candidates second and third.
Exit polls by public broadcaster NHK and other media showed Yoichi Masuzoe, a former television personality and one-time cabinet minister, came out top despite a relatively low turnout.
"I want to make Tokyo the number one city of the world, in areas including disaster prevention, welfare and the economy," Masuzoe told reporters.
"And above all, I will make the 2020 Olympic and Paralympic Games successful."
Turnout was put at around 34 per cent half an hour before the polls closed, more than 10 percentage points down on the previous election in the megacity, which on Saturday suffered the heaviest snowfall for nearly half a century.
The vote was called when the previous governor resigned after admitting he had been naive to accept Y50 million ($A548,400) from a scandal-mired hospital magnate.
