10:33 GMT: With the poll due to close in about 25 minutes (11:00 GMT) one of the concerns is low voter turnout. Government figures showed that as of 2 pm local time (05:00 GMT) voter turnout was 27.40 percent, down by 7.79 points from the previous 2009 poll.
Officials have been out trying to get people to the polls and in the Tokyo suburb of Abiko, my colleague Kyoko Hasegawa says a car from the municipal election board was driving around the streets playing a message over loudspeakers urging voters to "please cast your precious vote for the lower house election today."
Welcome to AFP's Live Report on Japan's elections in which voters seem likely to return conservatives to power at a time of growing tension with China and as the nation seeks to arrest economic decline.
Media surveys show the Liberal Democratic Party (LDP) on course for a convincing victory in the lower-house election, with the Democratic Party of Japan (DPJ) led by Prime Minister Yoshihiko Noda set to be ousted in the race for the premiership.
Some opinion polls even show the conservative LDP, with its coalition partner, achieving the two-thirds majority in the 480-seat chamber needed to override decisions by the upper house, in which no single party has a majority.
Noda's DPJ has disappointed voters who handed it a hefty majority in 2009 polls. Policy missteps, diplomatic gaffes and vicious factional infighting saw it burn through three premiers in as many years and squander its electoral hand.
Noda's plea in newspaper adverts Sunday for voters to "let us have another chance..." is unlikely to bring the electorate round with polls showing a win for the opposition Liberal Democratic Party (LDP), which ruled Japan almost continuously for more than five decades until it was ousted by the DPJ.
But commentators say victory for the LDP is due less to voter enthusiasm for the conservatives and more to their being seen as the least-worst option.