Japan's Crown Prince Naruhito and Princess Masako are to attend the coronation of Tonga's King Tupou VI on July 4th, followed by the luncheon hosted by the royal family.
Radio Tonga says the couple will represent the Japanese imperial family after an invitation from Tupou VI.
The couple will be in Tonga for four days.
King Tupou VI of Tonga speaks at the 68th United Nations General Assembly in September 2013 in New York. Photo: AFP
