The race to lead Japan's main ruling Liberal Democratic Party and the country will likely be a three-person contest. The winner will succeed Prime Minister Abe Shinzo, who announced last week he will step down over health issues.

Among the frontrunners, the government's top spokesperson is riding a wave of support that could prove impossible to beat.

More people in Japan crossed prefectural borders on the first weekend since the government eased restrictions on such travel.

Cell phone data show the number of people who went from Tokyo to other prefectures on Saturday and Sunday rose 11 percent from the previous week. Travel to Tokyo from other prefectures grew by 14 percent.