Japan's Emperor Akihito walks for a ritual called Taiirei-Tojitsu-Kashikodokoro-Omae-no-gi, a ceremony for the Emperor to report the conduct of the abdication ceremony, at the Imperial Palace in Tokyo, Japan April 30, 2019.
Naruhito, 59, technically succeeded his father just as Tuesday became Wednesday but his ascension to the Chrysanthemum Throne was formalised in a mid-morning ceremony, the first part of which his wife and other royal women were unable to attend.
In his address, Naruhito formally announced his succession and pledged to continue learning.
Naruhito noted that his father was devoted to praying for peace and sharing joys and sorrows of the people, while showing compassion.
Crown Prince Fumihito, 53, the younger brother of Emperor Naruhito, was on the emperor's right side in a black suit, while his wife Crown Princess Kiko, 52, and daughters Mako, 27, and Kako, 24, similarly all wore long white short-sleeve dresses, tiaras, necklaces, white gloves and sashes. But after a change in the rules to allow all cabinet ministers to attend, Satsuki Katayama, Japan's sole female cabinet member, was allowed to attend.
Nevertheless, Japan was in a festive mood as it celebrated an imperial succession prompted by retirement rather than death.
Former Emperor Akihito and Empress Michiko stepped down after three decades in their roles on Tuesday in a brief and simple ceremony, with Akihito thanking the people of Japan and saying he prayed for peace.
In his letter to Emperor Naruhito, PM Lee congratulated the monarch and said relations between Singapore and Japan are excellent, underpinned by many common interests, frequent high-level exchanges, robust economic links, and close people-to-people ties.
The role was redefined by Emperor Akihito, who helped fix the damage to Japan's reputation after the war.
Dozens of couples lined up at government offices to submit marriage documents to mark the first day of Naruhito's era, known as Reiwa, or "beautiful harmony".
Japanese media said two people were arrested.
Naruhito also faces uncertainties in the imperial household. Only his younger brother, Prince Akishino, 53, and Akishino's 12-year-old son, Prince Hisahito, can now succeed him. But she is not eligible to inherit the throne because of a males-only succession law that conservatives see as central to the imperial tradition but that many experts say threatens the very existence of the monarchy.
Though Masako struggled with a stress-related illness described by palace officials as an "adjustment disorder" that kept her largely out of the public eye for years, her public appearances have recently increased. But he said his father's work will be his guidepost.
Traditionally the coronation ceremony has been a men's-only event-even Naruhito's wife, Empress Masako, did not witness it. He graduated from Tokyo's prestigious Gakushuin University and the University of Oxford.