Chinese Premier Wen Jiabao has met his Japanese counterpart Shinzo Abe in Tokyo, at the start of a summit hailed as a sign of improved relations.
Mr Wen arrived in Tokyo amid pouring rain
The two men issued a joint statement promising to look frankly at their historical disputes, and signed accords on energy and the environment.
"Our talks will be a big step toward building strategically and mutually beneficial relations," Mr Abe said.
Mr Wen is the first Chinese prime minister to visit Japan in seven years.
The meeting followed a trip by Mr Abe to China in October - the first sign of a thaw in ongoing tensions between the two countries.
The Chinese leadership refused to talk to former Japanese Prime Minister Junichiro Koizumi because he insisted on visiting the Yasukuni shrine where Japan's war dead are honoured.
Japan's neighbours believe the shrine glorifies the country's wartime brutality.
Since Mr Koizumi was replaced by Mr Abe, there has been a noticeable change in attitude.
Mr Wen has only just arrived in Japan, but already the two sides are talking warmly of improved relations.
Responding to reports that Mr Wen considered this an "ice-melting" trip, a Japanese government spokesperson said: "We don't think there is any 'ice' left."
During his visit, Mr Wen is due to meet business leaders, as well as Japan's Emperor. He is also due to make a speech to parliament, and even join in a game of baseball.
But there remains much to discuss with Mr Abe and other senior politicians.
History: Japan's neighbours often think it has not done enough to atone for wartime atrocities
Trade: Bilateral trade is growing strongly
North Korea: Japan often takes a tougher stance than China over the nuclear issue
East China Sea: Beijing and Tokyo disagree over the boundary between their exclusive economic zones
Security: Japan wants to revise is pacifist constitution, which concerns China. China's military expansion concerns Japan
Japan - already China's biggest trading partner - wants to sell China technology that would allow it to become more energy efficient and help China reduce pollution.
Agreement on a Japanese proposal for a joint venture in the East China Sea, where there are believed to be significant reserves of oil and gas, will be harder to reach, according to the BBC's Chris Hogg in Tokyo.
Efforts to end North Korea's nuclear arms programme are also certain to be on the agenda.
Both sides support the six-nation agreement reached in February to disable North Korea's nuclear programme, but Tokyo often takes a tougher line on the issue than Beijing.
Japan says China is secretive about its rapidly growing defence budget, while Beijing is wary of plans to revise Japan's pacifist constitution to make it easier to deploy troops.
This remains an uneasy relationship, our correspondent says - and some experts believe the fact that face-to-face meetings are taking place at all is an achievement of some significance.