Government officials from Japan and North Korea are to meet for their first direct talks in four years.
The talks, in the Chinese capital Beijing, are expected to last for at least a day.
Japanese media say they will focus on the return of the remains of Japanese nationals who died in the north of the Korean peninsula during WW II.
But they will be watched for any thaw between the two sides, which have no diplomatic relations.
Analysts are also looking for indications of the future foreign policy direction of the new North Korean leadership under Kim Jong-un, who took over after his father Kim Jong-il died in December 2011.
Reports suggest Japan may raise the issue of the abduction of its citizens by Pyongyang to train spies in the 1970s and 1980s - a major point of contention.
North Korea has returned five of the abductees and says the rest are dead, but Japan wants more information.
When the two sides last met in 2008, Tokyo said Pyongyang agreed to reopen investigations, but no progress has been made on the issue.
Japan stressed that the meeting in Beijing was ''preparatory'', but that it could lead to other discussions.
"We have been working based on the principle of settling the unfortunate past and on restoring normal relations," Japan's chief cabinet secretary Osamu Fujimura said ahead of the talks.
Meanwhile, a group of Japanese arrived in Pyongyang on Tuesday on a 10-day trip aimed at reclaiming the remains of relatives who died in North Korea during WW II, reports said.
"Things have proceeded to a stage that is beyond what we had even hoped for. We are extremely grateful," Sadao Masaki, a representative of the group, told reporters in Beijing before heading to Pyongyang.
"Our final aim is to realise an improvement in relations between our two countries."
Japan colonised the Korean peninsula from 1910 to 1945. North Korea condemns Japan's treatment of ethnic Koreans during that period and its alliance with the US.
Japan is wary of Pyongyang's nuclear ambitions. Previous attempts by North Korea to launch rockets over its territory have also angered the Japanese.