Japanese Foreign Minister Taro Kono is visiting Beijing to ease the way for improving the long-strained ties between the two countries. So what is standing in the way of improving relations? Let's have a quick review.

In his talks with his Chinese counterpart Wang Yi on Sunday, Japanese Foreign Minister Taro Kono is expected to try to lay the groundwork for a long-postponed trilateral summit between Japan, China and South Korea. And, as this year is the 40th anniversary of the conclusion of the Treaty of Peace and Friendship between Japan and China, subsequent reciprocal visits by Prime Minister Shinzo Abe and Chinese President Xi Jinping will also be on the agenda.

Since Abe retook office as prime minister five years ago, reciprocal visits between Beijing and Tokyo have seen long delays. Of course, both Xi and Abe met several times on international occasions. This includes at recent APEC meetings and the 2016 G20 summit. But it's still too early to call those meeting turning points in the strained ties. Territorial disputes dog the relationship. These are centered on the Diaoyu Islands, a string of uninhabited islands and rocks in the East China Sea.

History is also a live issue between Japan and China. In 2014, China set up a national memorial day for the Nanjing Massacre. The day commemorates Chinese sacrifices and losses during the Japanese war of aggression during World War Two. But Abe provoked China's ire when he visited the Yasukuni Shrine in Tokyo, where both war dead and Class-A war criminals are honored.

And while Tokyo has not revised the 1993 apology to the comfort women -- known as the Kono statement-- nationalist politicians in Japan have been urging Prime Minister Shinzo Abe to water down the apology. By the way, the initial statement was made by Yohei Kono, father of the visiting foreign minister. Kono also plans to talk with Wang about the DPRK, in response to Pyongyang's nuclear and ballistic missile tests. This trip will be Kono's first to China as foreign minister and the first by any Japanese foreign minister since his predecessor Fumio Kishida visited in April 2016.