When he attended the World Water Forum in the Brazilian capital of Brasilia this past March, Crown Prince Naruhito told reporters that he gained a visceral sense for the latest world trend -- the recognition that solving problems concerning water will lead to world peace.

At a news conference in February on the occasion of his 58th birthday, the Crown Prince underscored the importance of responding to new societal demands when asked how he thought what the next emperor should do as the symbol of the state.

As for issues the Crown Prince believes the next emperor should tackle through official duties "to match the times," he cited natural disasters, poverty and environmental conservation, which are closely connected to water; problems plaguing children and senior citizens; Japan's friendship with other countries; and the development of domestic industries and technology.

Crown Prince Naruhito attaches particular importance to efforts to solve water-related problems. In the past, he delivered a speech on the issue at the United Nations headquarters in New York.

He has also been enthusiastic about performing official duties on behalf of Emperor Akihito. Since Emperor Hirohito passed away and Emperor Akihito acceded to the throne in January 1989, he has been first in the line of succession. He has performed acts in matter of state on behalf of the Emperor on 23 occasions when his father was on overseas trips or hospitalized. The Crown Prince has also attended ceremonies and banquets at the Imperial Palace on behalf of the Emperor.

A high-ranking Imperial Household Agency official said Crown Prince Naruhito "has always kept in mind his duty to act on behalf of His Majesty and sufficiently made preparations" to accede to the Imperial Throne.

Members of the Imperial Family perform imperial rites. The Emperor has attached particular importance to such rites, as he said in an August 2016 video message to the public suggesting his wish to abdicate, "I have considered that the first and foremost duty of the Emperor is to pray for peace and happiness of all the people." Traditionally, the Emperor and Empress and the Crown Prince and Crown Princess have performed imperial rituals.

What is worrisome is the health of Crown Princess Masako, who is to become empress in May next year. The Crown Princess, who was diagnosed with adjustment disorder in 2004, is still undergoing treatment. There are signs that the Crown Princess is recovering from her illness as she took her first overseas trip in two years in July 2015 and went on regional trips with her husband six times last year as part of her official duties. Still, she has not participated in court rites since she attended a ritual in April 2016. At the February 2017 news conference, the Crown Prince expressed hope that the public will continue to warmly watch over Crown Princess Masako's recovery.

A series of ceremonies connected to imperial succession will take place from May to November 2019. The Imperial Household Agency has urged the government's preparatory committee to secure a longer interval between two key enthronement ceremonies -- Sokuirei-Seiden-no-Gi, a ceremony in which enthronement will be officially proclaimed, and Daijosai, a ceremony in which the Emperor will offer new rice to imperial ancestors and to the deities of heaven and earth. The move is aimed at lessening the burden on those attending ceremonies relating to the Crown Prince's enthronement.

When Emperor Akihito acceded to the throne, Daijosai was held nine days after Sokuirei-Seiden-no-Gi, but the government has decided to extend the interval to 22 days for the Crown Prince and Princess. Behind the request is consideration given by the Emperor and Empress toward alleviating the burden on Crown Prince Naruhito and Crown Princess Masako.

The aforementioned senior Imperial Household Agency official said, "His Imperial Highness the Crown Prince and Her Imperial Highness the Crown Princess frequently discuss their future duties. Their Majesties are warmly watching over the Crown Prince and Crown Princess as they recall the Emperor's own enthronement."

With the impending abdication and enthronement, Crown Prince Naruhito and Crown Princess Masako are exploring what being a new "symbol" of the State will entail.

(This is part three of a five-part series)