Former health minister Yoichi Masuzoe, who entered the Feb. 9 Tokyo gubernatorial election Tuesday, said he welcomed all challengers, including ex-Prime Minister Morihiro Hosokawa.

"I think it's good to have policy debates openly and squarely by eligible candidates in a democratic society, and it doesn't matter to me who declares," Masuzoe told reporters at the metropolitan government building. "What comes first is the policy for Tokyo."

Asked about the hot-button topic of nuclear energy, the 65-year-old former Upper House member said he has supported its phaseout ever since he visited Fukushima Prefecture after the March 2011 earthquake and tsunami.

"I think most of the public would agree to a society that doesn't rely on nuclear power," Masuzoe said. "But what's important is to think about alternative energy sources once the nuclear energy fades out."

But his key goal, Masuzoe said, was to hold the best Olympics and Paralympics ever in 2020.

"We didn't have much good news in the past 20 years during deflation," Masuzoe said. "But we will have the Olympics and Paralympics in six years, so I'd like to help Tokyo and Japan be more active (toward 2020)."

Masuzoe also said he would take steps to prepare the capital for natural disasters, including by enhancing infrastructure, and strengthen the welfare system by making the most of his experience as health minister.