Twenty-five years ago, when China was isolated by the world, officials in Tokyo offered a lifeline.
After the bloody crackdown in Tiananmen Square, many countries cut diplomatic ties with Beijing. Japan's prime minister at the time, Toshiki Kaifu, travelled to Beijing in 1991 on an official visit. In doing so, he became the first of what Beijing considered Western leaders to visit.
In his memoir, Ten Episodes in China's Diplomacy, ex-vice-premier and foreign minister Qian Qichen said Japan was reluctant to support sanctions and was quick to resume assistance loans in 1990.
"Of course, Japan did this for its own interests. But as the weakest link in Western sanctions against China, Japan has provided the best point of breakthrough for China to break Western sanctions," Qian wrote.
Gao Hong, deputy director of Japanese studies at the Chinese Academy of Social Sciences, said the two countries' relationship was largely stable in the 1980s.
"At that time, many people in power had gone through the war [against China], they still remembered the harm Japan caused to China," Gao said.
But he said Japan was also supportive of China's economic reform. "This benefited Japan's own economy," he added.
At the height of China's isolation, countries still tried - secretly and publicly - to stabilise their relationships with it.
Less than a month after Tiananmen, US president George H.W.Bush sent his national security adviser, Brent Scowcroft, and deputy secretary of state, Lawrence Eagleburger, on a secret trip to Beijing, according to Qian's book and US accounts.
According to Qian, Scowcroft told leader Deng Xiaoping at a meeting that Bush had sent his envoys to "uphold bilateral relationships".
Along with Japan, many Asian and developing countries were also more open to China in the few years after 1989, according to veteran diplomat Wu Jianmin. He said Western businesses also maintained relationships with China despite their governments' reluctance to engage.