Japan's Emperor Naruhito with Empress Masako, second right, their daughter Princess Aiko, right, Crown Prince Akishino, third left, Crown Princess Kiko, second left, and their daughter Princess Kako, left, as they appear on the balcony of the Imperial Palace to mark the emperor's 63th birthday in Tokyo Thursday, Feb. 23, 2023, in Tokyo. Eugene Hoshiko/Pool via REUTERS 

TOKYO, JAPAN - FEBRUARY 23: (From R) Japanese Crown Prince Fumihito, Crown Princess Kiko and Princess Kako greet the public on Emperor Naruhito's birthday on February 23, 2023 in Tokyo, Japan. Takashi Aoyama/Pool via REUTERS 

Japan's Emperor Naruhito delivers a speech as Empress Masako, second right, their daughter Princess Aiko, right, Crown Prince Akishino, third left, Crown Princess Kiko, second left, and their daughter Princess Kako, left, appear on the balcony of the Imperial Palace to mark the emperor's 63th birthday in Tokyo Thursday, Feb. 23, 2023, in Tokyo. Eugene Hoshiko/Pool via REUTERS 

Japan's imperial family members: Former Empress Michiko, former Emperor Akihito, Emperor Naruhito, Empress Masako, Princess Aiko, Crown Prince Akishino, Crown Princess Kiko and Princess Kako waves to well-wishers for the New Year's greetings at the Imperial Palace in Tokyo on January 2, 2023, the first time in three years. YOSHIKAZU TSUNO/Pool via REUTERS 

Japan's imperial family members, former Empress Michiko, former Emperor Akihito, Emperor Naruhito, Empress Masako, Princess Aiko, Crown Prince Akishino and Crown Princess Kiko waves to well-wishers for the New Year's greetings at the Imperial Palace in Tokyo on January 2, 2023, the first time in three years. YOSHIKAZU TSUNO/Pool via REUTERS 

TOKYO, JAPAN - JANUARY 02: Emperor Emeritus Akihito, Empress Emerita Michiko, Emperor Naruhito, Empress Masako, Crown Prince Fumihito of Akishino and Crown Princess Kiko of Akishino attend the New Year's appearance by the Japanese royal family at the Imperial Palace on January 2, 2023 in Tokyo, Japan. The event was held for the first time in three years, following a hiatus due to the coronavirus pandemic. Tomohiro Ohsumi/Pool via REUTERS 

TOKYO, JAPAN - JANUARY 02: Emperor Emeritus Akihito, Empress Emerita Michiko, Emperor Naruhito, Empress Masako, Princess Aiko, Crown Prince Fumihito of Akishino, Crown Princess Kiko of Akishino and Princess Kako of Akishino wave during the New Year's appearance by the Japanese royal family at the Imperial Palace on January 2, 2023 in Tokyo, Japan. The event was held for the first time in three years, following a hiatus due to the coronavirus pandemic. Tomohiro Ohsumi/Pool via REUTERS 

TOKYO, JAPAN - JANUARY 02: Princess Akiko of Mikasa, Princess Nobuko of Mikasa, Emperor Emeritus Akihito, Empress Emerita Michiko, Emperor Naruhito, Empress Masako, Princess Aiko, Crown Prince Fumihito of Akishino, Crown Princess Kiko of Akishino, Princess Kako of Akishino, Princess Hisako of Takamado and Princess Tsuguko of Takamado wave during the New Year's appearance by the Japanese royal family at the Imperial Palace on January 2, 2023 in Tokyo, Japan. The event was held for the first time in three years, following a hiatus due to the coronavirus pandemic. Tomohiro Ohsumi/Pool via REUTERS 

TOKYO, JAPAN - JANUARY 02: Emperor Emeritus Akihito, Empress Emerita Michiko, Emperor Naruhito, Empress Masako, Princess Aiko, Crown Prince Fumihito of Akishino, Crown Princess Kiko of Akishino and Princess Kako of Akishino attend the New Year's appearance by the Japanese royal family at the Imperial Palace on January 2, 2023 in Tokyo, Japan. The event was held for the first time in three years, following a hiatus due to the coronavirus pandemic. Tomohiro Ohsumi/Pool via REUTERS 

Former Japanese emperor Akihito, former empress Michiko, Japan's Emperor Naruhito, Empress Masako, their daughter Princess Aiko, Crown Prince Akishino, Crown Princess Kiko and their daughter Princess Kako appear before well-wishers during the traditional New Year's greeting ceremony by Japan's royal family at the Imperial Palace in Tokyo on January 2, 2023. PHILIP FONG/Pool via REUTERS 

Japanese Princess Aiko, daughter of Emperor Naruhito chats with Crown Prince Akishino and Crown Princess Kiko as they attend the New Year's greetings at the Imperial Palace in Tokyo on January 2, 2023, the first time in three years. YOSHIKAZU TSUNO/Pool via REUTERS 

TOKYO, JAPAN - JANUARY 02: (L-R) Princess Tsuguko of Takamado, Princess Hisako of Takamado, Princess Hanako of Hitachi, Prince Hitachi, Emperor Emeritus Akihito, Empress Emerita Michiko, Emperor Naruhito, Empress Masako, Princess Aiko, Crown Prince Fumihito of Akishino, Crown Princess Kiko of Akishino, Princess Kako of Akishino, Princess Yuriko of Mikasa, Princess Nobuko of Mikasa and Princess Akiko of Mikasa during the New Year's appearance by the Japanese royal family at the Imperial Palace on January 2, 2023 in Tokyo, Japan. The event was held for the first time in three years, following a hiatus due to the coronavirus pandemic. Tomohiro Ohsumi/Pool via REUTERS 

Japan's Crown Prince Akishino and Crown Princess Kiko waves to a special flight carrying Emperor Naruhito and Empress Masako, heading for the UK to attend Britain's Queen Elizabeth's funeral, as the plane takes off at Haneda international airport in Tokyo, Japan September 17, 2022. REUTERS/Issei Kato 

Japan's Crown Prince Akishino and Crown Princess Kiko waves to a special flight transporting Emperor Naruhito and Empress Masako, heading for the UK to attend Britain's Queen Elizabeth's funeral, as the plane takes off at Haneda International Airport in Tokyo, Japan September 17, 2022. REUTERS/Issei Kato 

Japan's Emperor Naruhito and Empress Masako, accompanied by Crown Prince Akishino and Crown Princess Kiko, walk toward to a special flight heading for the UK to attend Britain's Queen Elizabeth's funeral, at Haneda international airport in Tokyo, Japan September 17, 2022. REUTERS/Issei Kato 

Japan's Emperor Naruhito and Empress Masako, accompanied by Crown Prince Akishino and Crown Princess Kiko, walk toward to a special flight heading for the UK to attend Britain's Queen Elizabeth's funeral, at Haneda international airport in Tokyo, Japan September 17, 2022. REUTERS/Issei Kato 

Crown Prince Fumihito leaves the Imperial Palace after being formally declared first in line to the Chrysanthemum Throne during a ceremony in which Emperor Naruhito proclaimed his younger brother "Crown Prince to the People of Japan" in Tokyo, Japan, November 8, 2020. Carl Court/Pool via REUTERS 

Crown Prince Fumihito leaves the Imperial Palace after being formally declared first in line to the Chrysanthemum Throne during a ceremony in which Emperor Naruhito proclaimed his younger brother "Crown Prince to the People of Japan" in Tokyo, Japan, November 8, 2020. Carl Court/Pool via REUTERS 

Crown Prince Fumihito leaves the Imperial Palace after being formally declared first in line to the Chrysanthemum Throne during a ceremony in which Emperor Naruhito proclaimed his younger brother "Crown Prince to the People of Japan" in Tokyo, Japan, November 8, 2020. Carl Court/Pool via REUTERS 

Crown Prince Fumihito leaves the Imperial Palace after being formally declared first in line to the Chrysanthemum Throne during a ceremony in which Emperor Naruhito proclaimed his younger brother "Crown Prince to the People of Japan" in Tokyo, Japan, November 8, 2020. Carl Court/Pool via REUTERS 

Crown Prince Fumihito leaves the Imperial Palace after being formally declared first in line to the Chrysanthemum Throne during a ceremony in which Emperor Naruhito proclaimed his younger brother "Crown Prince to the People of Japan" in Tokyo, Japan, November 8, 2020. Carl Court/Pool via REUTERS 

Crown Prince Fumihito leaves the Imperial Palace after being formally declared first in line to the Chrysanthemum Throne during a ceremony in which Emperor Naruhito proclaimed his younger brother "Crown Prince to the People of Japan" in Tokyo, Japan, November 8, 2020. Carl Court/Pool via REUTERS 

Crown Prince Fumihito leaves the Imperial Palace after being formally declared first in line to the Chrysanthemum Throne during a ceremony in which Emperor Naruhito proclaimed his younger brother "Crown Prince to the People of Japan" in Tokyo, Japan, November 8, 2020. Carl Court/Pool via REUTERS 

Crown Prince Fumihito leaves the Imperial Palace after being formally declared first in line to the Chrysanthemum Throne during a ceremony in which Emperor Naruhito proclaimed his younger brother "Crown Prince to the People of Japan" in Tokyo, Japan, November 8, 2020. Carl Court/Pool via REUTERS 

Japan's Emperor Naruhito, Empress Masako, Crown Prince Akishino, Crown Princess Kiko and Princess Mako attend a public appearance for New Year celebrations at the Imperial Palace in Tokyo, Japan, January 2, 2020. REUTERS/Kim Kyung-Hoon 

Japan's Empress Emerita Michiko, Emperor Emeritus Akihito, Emperor Naruhito, Empress Masako, Crown Prince Akishino and Crown Princess Kiko wave to well-wishers during a public appearance for New Year celebrations at the Imperial Palace in Tokyo, Japan, January 2, 2020. REUTERS/Kim Kyung-Hoon 

Crown Prince Frederik and Crown Princess Mary of Denmark arrive at the cocktail party before the banquet for newly enthroned Emperor Naruhito and Empress Masako hosted by the Prime Minister of Japan Shinzo Abe and his spouse in Tokyo, Japan, October 23, 2019. Pool via REUTERS 

Japan's Crown Prince Akishino leaves at the end of the enthronement ceremony of Japan's Emperor Naruhito at the Imperial Palace in Tokyo, Japan October 22, 2019. Kazuhiro Nogi/Pool via REUTERS 

Japan's Crown Prince Akishino attends the enthronement ceremony of Japan's Emperor Naruhito at the Imperial Palace in Tokyo, Japan October 22, 2019. Kazuhiro Nogi/Pool via REUTERS 

Japan's Crown Prince Akishino leaves the ceremony hall with Crown Princess Akishino after the enthronement ceremony of his brother, Japan's Emperor Naruhito, at the Imperial Palace in Tokyo, Japan October 22, 2019. Kimimasa Mayama/Pool via REUTERS 

Danish Crown Prince Frederik and Crown Princess Mary arrive for the enthronement ceremony of Japan's Emperor Naruhito at the Imperial Palace in Tokyo, Japan October 22, 2019. Carl Court/Pool via REUTERS 

Japan's Crown Prince Akishino leaves the ceremony hall after his brother Japan's Emperor Naruhito proclaimed his enthronement at the Imperial Palace in Tokyo, Japan, October 22, 2019. Kimimasa Mayama/Pool via REUTERS 

Japan's Crown Prince Akishino arrives for a ceremony to proclaim Emperor Naruhito's enthronement to the world, called Sokuirei-Seiden-no-gi, at the Imperial Palace in Tokyo, Japan October 22, 2019. REUTERS/Issei Kato/Pool 

Norway's Crown Prince Haakon arrives at the Imperial Palace to attend the proclamation ceremony of the enthronement of Japan's Emperor Naruhito in Tokyo, Japan, October 22, 2019. Koji Sasahara/Pool via REUTERS 

Japan's Crown Prince Akishino arrives at the ceremony site where Emperor Naruhito will report the conduct of the enthronement ceremony at the Imperial Sanctuary inside the Imperial Palace in Tokyo, Japan October 22, 2019. REUTERS/Kim Hong-ji REFILE - CORRECTING TITLE 

Japan's Crown Prince Akishino and Crown Princess Kiko arrive at the ceremony site where Emperor Naruhito will report the conduct of the enthronement ceremony at the Imperial Sanctuary inside the Imperial Palace in Tokyo, Japan October 22, 2019. REUTERS/Kim Hong-ji REFILE - CORRECTING TITLE 

Japan's Crown Prince Akishino and Crown Princess Kiko arrive at the ceremony site where Emperor Naruhito will report the conduct of the enthronement ceremony at the Imperial Sanctuary inside the Imperial Palace in Tokyo, Japan October 22, 2019. REUTERS/Kim Hong-ji REFILE - CORRECTING TITLE 

Saudi Arabia's Crown Prince Mohammed bin Salman is welcomed by Japan's Emperor Naruhito upon his arrival at the Togu Palace in Tokyo, Japan, July 2, 2019. REUTERS/Issei Kato/Pool 

Saudi Arabia's Crown Prince Mohammed bin Salman is welcomed by Japan's Emperor Naruhito upon his arrival at the Togu Palace in Tokyo, Japan, July 2, 2019. REUTERS/Issei Kato/Pool 

Saudi Arabia's Crown Prince Mohammed bin Salman is welcomed by Japan's Emperor Naruhito upon his arrival at the Togu Palace in Tokyo, Japan, July 2, 2019. REUTERS/Issei Kato/Pool 

Japan's Emperor Naruhito, Empress Masako, Crown Prince Akishino and Crown Princess Kiko, with their daughters Princess Mako and Princess Kako, greet well-wishers during their first public appearance at the Imperial Palace in Tokyo, Japan May 4, 2019. REUTERS/Issei Kato 

Japan's Emperor Naruhito, Empress Masako, Crown Prince Akishino and Crown Princess Kiko greet well-wishers during their first public appearance at the Imperial Palace in Tokyo, Japan May 4, 2019. REUTERS/Issei Kato 

Japan's Emperor Naruhito, Empress Masako, Crown Prince Akishino and Crown Princess Kiko greet well-wishers during their first public appearance at the Imperial Palace in Tokyo, Japan May 4, 2019. REUTERS/Issei Kato 

Japan's Emperor Naruhito, Empress Masako, Crown Prince Akishino and Crown Princess Kiko, with their daughters Princess Mako and Princess Kako, greet well-wishers during their first public appearance at the Imperial Palace in Tokyo, Japan May 4, 2019. REUTERS/Issei Kato 

Japan's Emperor Naruhito, Empress Masako, Crown Prince Akishino, Crown Princess Kiko and other members of the royal family greet well-wishers during a public appearance at the Imperial Palace in Tokyo, Japan May 4, 2019. REUTERS/Issei Kato 

Japan's Emperor Naruhito, Empress Masako, Crown Prince Akishino and Crown Princess Kiko greet well-wishers during their first public appearance at the Imperial Palace in Tokyo, Japan May 4, 2019. REUTERS/Issei Kato 

Japan's Crown Prince Akishino looks on as Emperor Naruhito and Empress Masako greet well-wishers during their first public appearance at the Imperial Palace in Tokyo, Japan May 4, 2019. REUTERS/Issei Kato 

Japan's Emperor Naruhito and Crown Prince Akishino greet well-wishers during their first public appearance at the Imperial Palace in Tokyo, Japan May 4, 2019. REUTERS/Issei Kato 

Japan's Emperor Naruhito, Empress Masako, Crown Prince Akishino and Crown Princess Kiko greet well-wishers during their first public appearance at the Imperial Palace in Tokyo, Japan May 4, 2019. REUTERS/Issei Kato 

Japan's Emperor Naruhito, Empress Masako, Crown Prince Akishino and Crown Princess Kiko greet well-wishers during their first public appearance at the Imperial Palace in Tokyo, Japan May 4, 2019. REUTERS/Issei Kato 

Japan's Emperor Naruhito, Empress Masako, Crown Prince Akishino, Crown Princess Kiko and other members of the royal family greet well-wishers during a public appearance at the Imperial Palace in Tokyo, Japan May 4, 2019. REUTERS/Issei Kato 

Japan's Emperor Naruhito, Empress Masako, Crown Prince Akishino and Crown Princess Kiko attend a ceremony called Sokui-go-Choken-no-gi, his first audience after the accession to the throne, at the Imperial Palace in Tokyo, May 1, 2019, in this photo released by Imperial Household Agency of Japan. Imperial Household Agency of Japan/Handout via Reuters ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. 

Japan's Crown Prince Naruhito and Crown Princess Masako arrive at the Imperial Palace, where Emperor Akihito will abdicate in a royal ceremony, in Tokyo, Japan, April 30, 2019. REUTERS/Kim Kyung-Hoon 

Japan's Crown Prince Naruhito and Crown Princess Masako arrive at the Imperial Palace, where Emperor Akihito will abdicate in a royal ceremony, in Tokyo, Japan, April 30, 2019. REUTERS/Kim Kyung-Hoon 

Japan's Crown Prince Naruhito and Crown Princess Masako arrive at the Imperial Palace, where Emperor Akihito will abdicate in a royal ceremony, in Tokyo, Japan, April 30, 2019. REUTERS/Kim Kyung-Hoon 

Japan's Crown Prince Naruhito and Crown Princess Masako arrive at the Imperial Palace, where Emperor Akihito will abdicate in a royal ceremony, in Tokyo, Japan, April 30, 2019. REUTERS/Kim Kyung-Hoon 

Royal aficionado Fumiko Shirataki, 78, and her friends photograph Japan's Crown Prince Naruhito, Crown Princess Masako and their daughter Princess Aiko at Tokyo Station in Tokyo, Japan, March 25, 2019. REUTERS/Issei Kato SEARCH "EMPEROR FAN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

Royal aficionado Fumiko Shirataki, 78, and her friends rush to secure their photo position before arrival of Japan's Crown Prince Naruhito, Crown Princess Masako and their daughter Princess Aiko, at Tokyo Station in Tokyo, Japan, March 25, 2019. REUTERS/Issei Kato SEARCH "EMPEROR FAN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.