Twenty years after China and Japan restored diplomatic ties, the two great powers of Asia remain haunted by the bitter legacy of World War II despite markedly improved relations.
The first visit to China by a Japanese emperor - nearly two millennia after the first documentary reference to contact between the countries - will be the main event to mark the anniversary this fall.The trip - to be formally announced Tuesday, barring any last-minute problems - is being hailed as a symbol of a budding friendship in which the neighbors are joining hands to forge stronger economic ties.
But Emperor Akihito's visit almost didn't come off, primarily because conservatives in Japan's ruling party were afraid he would be expected to offer a strong apology for Japan's wartime occupation of China - something his father, the late Emperor Hirohito, never did.
Chinese Communist Party chief Jiang Zemin has said it is up to Japan whether to offer an apology, and China formally waived any claims for war reparations when it established diplomatic relations with Japan in 1972.
But many Chinese citizens remain bitter about Japan's failure to fully acknowledge its wartime atrocities.
With the end of the Cold War, Japan, with its economic power, and China, with its 1.1 billion people, want to work together to keep East Asia stable.
Amicable ties are so important to Tokyo that it was the first country to ease sanctions imposed by the Western powers on China for the 1989 military crackdown on pro-democracy protesters.
Japan responded to criticism of its quick rapprochement by arguing that encouraging paramount leader Deng Xiaoping's economic liberalization and open-door policy will lead to improvement in China's human rights record.
After briefly freezing aid in 1989, Japan is once again China's largest source of bilateral aid, providing $6 billion in development loans over 1990-95.
Although direct investment in China has lagged, accounting for just 1 percent of all Japanese overseas investment since 1951, China hopes its huge market potential and capitalist-style economic reforms will encourage more Japanese entrepreneurs to set up shop.