The visit to Yasukuni shrine, marking the anniversary of Japan's surrender in World War II, is a regular sore point for Tokyo's neighbours, but the latest trip comes with relations plumbing new depths as territorial disputes exacerbate tensions.
Japan's nationalist Prime Minister Shinzo Abe visited the shrine in December, sparking fury in Asia and earning him a diplomatic slap on the wrist from the United States, a close ally, which said it was "disappointed" by the move.
Abe has remained tight-lipped about another visit, but local media have said he was likely to stay away on the 69th anniversary as he looks to mend ties with Beijing and Seoul.
China and Japan have a bloody history and are currently embroiled in a bitter row over islands in the East China Sea, which has clouded Abe's bid to hold talks with Chinese President Xi Jinping at a regional meeting in Beijing in November.
Abe and Xi, both strong nationalists, have not held a bilateral summit since they both came to power more than 18 months ago.
Last year, Abe broke with two decades of tradition by omitting any expression of remorse for Tokyo's past aggression in Asia when he spoke at an annual anniversary ceremony attended by Emperor Akihito and Empress Michiko.
The shrine honours some 2.5 million citizens who died in World War II and other conflicts, including 14 indicted war criminals such as General Hideki Tojo, who authorised the attack on Pearl Harbour, drawing the United States into the war.
Many ordinary people visit the shrine to pay their respects to family and friends who died in combat.
But visits by Japanese politicians enrage neighbouring nations, which view them as an insult and a painful reminder of Tokyo's aggression in the first half of the 20th century, including a brutal 35-year occupation of the Korean peninsula.
On last year's surrender anniversary, some 100 lawmakers as well as three state ministers visited the shrine near the Imperial Palace in downtown Tokyo.
Japan's hawkish premier has defended the visits, but key ministers, including Abe's deputy Taro Aso and Foreign Minister Fumio Kishida, have stayed away.
Since taking power in December 2012, Abe has mostly focused his attention on stoking the country's economy, but he has also started to push for a more robust defence policy.
Last month, Tokyo invoked the right to allow its military to go into battle in defence of allies, a major shift for the Pacifist nation that came despite widespread public opposition.