Crown Prince Naruhito, the heir to the Japanese imperial throne and whose ascension is set for May 1 next year, departed Friday on a five-day trip to Brazil to attend the World Water Forum.

The eldest son of Emperor Akihito left from Narita airport and is expected to arrive in Brasilia on Sunday morning after transiting in Miami in the United States.

(Pool photo)

The 58-year-old prince will visit a local agricultural research facility and meet with Brazilians of Japanese descent in the country on the day he arrives.

He is scheduled to give an address in English at the opening ceremony of the Eighth World Water Forum on Monday and deliver a keynote speech there.

During what the Imperial Household Agency views as a personal trip, the crown prince is also expected to have lunch with Brazilian President Michel Temer. He will leave Brasilia on Tuesday to return to Tokyo on Thursday.

Crown Prince Naruhito, who has made research into water issues his life's work, attended the triennial World Water Forum in Kyoto, Mexico and Turkey.

He is set to ascend the Chrysanthemum throne after Emperor Akihito relinquishes it on April 30 next year in what would be Japan's first imperial abdication in more than 200 years.