Japan and South Korea are marking the 50th anniversary of the restoration of diplomatic ties. But lately, relations between the 2 nations have been strained. Ties date back over a thousand years. In the 17th century, Korean kings sent representatives to Japan to strengthen ties. The practice lasted for 2-and-a-half centuries.Now a group of Japanese and South Koreans has retraced the steps of one of the early diplomatic missions in an effort to promote peace and reinforce their bond. The participants covered about 1,200 kilometers in 52 days. They traveled by foot, ferry and bus. Others joined along the way, with a total of 2,600 people taking part. On Friday, they arrived in Tokyo, completing their journey.