The South Korean presidential office is emphasizing that President Park Geun-hye and Chinese President Xi Jinping's special friendship was a key factor behind Xi's state visit to Seoul.
It's the first time a Chinese leader is coming to South Korea before paying a visit to Beijing's traditional ally, North Korea, and neighboring Japan.
Presidents Park and Xi, who first met in 2005, have made strong impressions on each other, and since taking office last year, they have met four times.
President Xi's decision to visit Seoul first will put more pressure on Pyongyang to lay down its nuclear weapons and return to negotiations.
Now the question is exactly how the two leaders will deliver their positions in a joint statement following Thursday's summit.
"While South Korea wants a concrete expression of opposition to North Korea's fourth nuclear test, China wants to keep the general term 'denuclearization of the Korean peninsula.'"
Also topping the agenda for the talks will be Tokyo's retreat from a historical apology to Seoul and its attempts to expand its military presence.
Beijing, locked in a bitter territorial dispute with Tokyo, is expected to seek greater cooperation with Seoul on historical issues, but it's unlikely Presidents Park and Xi will specifically target Japan.
The amicable relations between Seoul and Beijing, and their mutual mistrust of Tokyo, is not a welcoming dynamic for Washington, which is looking to expand its influence in Asia.
"China has been pressuring Korea not to take part in the U.S.-led anti-ballistic missile defense system. The U.S., on the other hand, has been urging Korea to take caution in participating in the China-led Asian Infrastructure Investment Bank."
On the economic front, the leaders of Korea and China will agree to speed up their FTA negotiations and set up a trade market for their respective currencies.
Choi You-sun, Arirang News.