Campaigning began yesterday in an election expected to strengthen Prime Minister Shinzo Abe's control over parliament, ushering in the stability he needs to fix Japan's floundering economy.
Voters nationwide will go to the polls on July 21 to elect half of the 242 seats in the upper house of the legislature.
With approval ratings as high as 70 per cent, Abe is expected to romp home, bagging control of both chambers and not having to face a public vote for three years.
Supporters said he would use that political clout to force changes on cosseted and inefficient industries, such as agriculture, and to cut a swathe through labour laws that businesses claim make it too difficult to hire and fire workers.
Detractors said he would abandon the economic project of his first six months and get back on his hobby horse - revising the constitution, boosting the military and reassessing Japan's wartime history.
"We will regain a strong economy that will boost reconstruction" from the earthquake-tsunami-nuclear disaster of 2011, Abe said as he kicked off his campaign at a railway station in Fukushima, about 50 kilometres from the crippled atomic plant.
Banri Kaieda, leader of the largest opposition Democratic Party of Japan (DPJ), began the day in Iwate, one of the prefectures hardest hit by the 2011 tsunami.
For the first time in Japanese politics, internet election campaigns are allowed in the upper house vote, with candidates and parties permitted to post updates to their followers on Facebook and Twitter.
Opponents say the premier's focus on the economy is a ruse designed to fool voters into giving him enough power to change Japan's pacifist constitution.
They say with a majority in both houses, he will look to bolster the country's already well-equipped armed forces and switch their role from that of a self-defence force to a full-fledged military.
They point to his ministers visiting the Yasukuni shrine, the believed repository of the souls of about 2.5 million war dead - including 14 leading war criminals - and a place seen by Japan's Asian neighbours as a symbol of Tokyo's imperialist past.
No party at present controls the upper chamber, although the DPJ has been the single largest grouping during the past few years.
However, their drubbing in December's general election when Abe's Liberal Democratic Party swept to power, combined with vicious factional infighting, has left them in disarray.
They and other challengers are struggling to find a coherent message to sell to voters, who have on the whole warmed to Abenomics and the green shoots of economic growth it has nurtured.