The Prince of Wales has arrived in Japan on a two-day visit, Clarence House said.
Charles has undertaken the official visit at the request of the British Government to attend the ceremony of enthronement of Emperor Naruhito on Tuesday.
The visit includes a day of engagements in Tokyo to celebrate British-Japanese connections.
Charles, who is going on behalf of the Queen, has been to Japan four times before and last visited in 2008.
Emperor Naruhito acceded to the Chrysanthemum Throne upon the abdication of his father, Emperor Akihito, on May 1 2019.
Charles attended the ceremony of enthronement of Emperor Akihito on November 12 1990.