Tokyo has high hopes that an eight-day visit by Hu Deping , the son of the late Chinese leader Hu Yaobang , will help repair strained ties, although analysts warn that a significant breakthrough is unlikely.
Riding on his father's legacy as a friend of Japan and with direct access to China's top leadership, the retired "princeling" is widely seen as an unofficial envoy to engage with Japanese leaders at a time when stalled high-level exchanges have stalled.
Analysts say Hu's unique role has allowed flexibility for both sides to test the waters on how to push forward the relationship, which has sunk to a new low over disagreements about territorial and historical issues.
Hu arrived in Tokyo on Saturday after being invited by Japan's foreign ministry. Travelling in a personal capacity, Hu has met senior officials including Chief Cabinet Secretary Yoshihide Suga and Foreign Minister Fumio Kishida.
In his meeting with Suga on Tuesday, Hu emphasised the need for co-operation instead of confrontation."Japan and China are inseparable in terms of economics and we have to continue to deepen exchanges," Hu told Suga during their discussions.
Suga replied: "What is important is for us to develop a mutually beneficial relationship that is based on common strategic interests."
Kishida emphasised in his meeting with Hu that it was important for Tokyo and Beijing to advance their relationship despite having problems over individual issues.
Hu also gave a speech at an event attended by 10 Japanese politicians, during which he delivered a similar message.
He is also expected to meet former prime minister Yasuhiro Nakasone before leaving Japan on Sunday.
Nakasone forged a close working relationship with Hu's father when Hu Yaobang was general secretary of the Communist Party.
Zhou Yongsheng , a professor from China Foreign Affairs University, said that while Hu was visiting as a private citizen, his direct access to the central leadership underscored Beijing's desire to repair ties.
Sending an unofficial envoy, Zhou said, allowed room to manoeuvre and more flexibility when discussing issues. But whether the trip could make any headway still depended on whether Tokyo could meet Beijing half way.
Zhou said one key task for Hu was asking Shinzo Abe not to visit the controversial Yasukuni Shrine again in his capacity as prime minister.
Abe's shrine visit late last year sparked a fierce response from Beijing, further straining a delicate relationship frayed by disputes over the East China Sea.
"But if Japan will not compromise on these matters of principle, this trip will not make much difference," Zhou said.
Japanese observers are also sceptical about the impact of Hu's visit. "It appears that Japan is trying to find a way to make relations better and various areas of potential co-operation are being examined," Go Ito, a professor of international relations at Tokyo's Meiji University, said.
"Japan's attitude is that it has welcomed China's response to its request for Hu to visit but it also recognises that he is only here because there is at present a complete absence of any other form of discussions."