By Tim Kelly and Mariko Katsumura TOKYO (Reuters) -Japanese voters headed to the polls on Sunday in a tightly contested upper house election that could unleash political turmoil, with rising prices and immigration concerns threatening to weaken Prime Minister Shigeru Ishiba's grip on power.

Opinion polls suggest Ishiba’s Liberal Democratic Party may fall short of a majority in Upper House elections.

Japanese Prime Minister Shigeru Ishiba faces a reckoning from voters on Sunday with upper house elections that could end his premiership and see a right-wing populist party make inroads.One making inroads is the "Japanese-first" Sanseito,

Japanese voters headed to the polls on Sunday to cast ballots for seats in the parliament’s upper chamber, in an election that could put Prime Minister Shigeru Ishiba’s ruling coalition on rocky

Shinjiro Koizumi has scrambled to cut soaring rice prices ahead of a high-stakes election this weekend. Will it be enough to buoy support for the Liberal Democratic Party?

Decontaminated but slightly radioactive soil from Fukushima has been delivered to the Japanese prime minister’s office to be reused in an effort to showcase its safety.

Japanese Finance Minister Katsunobu Kato said on Friday he was aware of bond market concerns about the country's fiscal policy ahead, in the build-up to an upper house election where the minority government is poised for another setback.