Japanese Royal Family Celebrates New Year at the Imperial Palace in Tokyo on Jan. 1, 2018.

Emperor Akihito (far L), Empress Michiko (2nd from L) and other members of Japan's imperial family attend a New Year's ceremony at the Imperial Palace in Tokyo on Jan. 1, 2018.

Japanese Emperor Akihito (L) and Empress Michiko attend a New Year's ceremony at the Imperial Palace in Tokyo on Jan. 1, 2018.

Emperor Akihito (far L), Empress Michiko (2nd from L) and other members of Japan's Imperial family attend a New Year's ceremony at the Imperial Palace in Tokyo on Jan. 1, 2018.

Japanese Emperor Akihito (C), Empress Michiko (far R) and their sons -- Prince Akishino (far L) and Crown Prince Naruhito -- attend a New Year's ceremony at the Imperial Palace in Tokyo on Jan. 1, 2018.

Japan's Crown Princess Masako smiles during the royal family's annual New Year's greeting to well-wishers gathered at the Imperial Palace in Tokyo on January 2, 2018.

Japans Prince Akishino (L), Princess Kiko (C) and their daughter Princess Mako (R) wave during the royal family's annual New Year's greeting to well-wishers gathered at the Imperial Palace in Tokyo on January 2, 2018.

Emperor Akihito and Empress Michiko greet well-wishers from a balcony at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

Emperor Akihito and Empress Michiko greet well-wishers from a balcony at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

Crown Prince Naruhito, greet well-wishers from a balcony at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

(L to R) Crown Princess Masako and Crown Prince Naruhito, greet well-wishers from a balcony at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

Japan's Princess Mako, the eldest granddaughter of Emperor Akihito and Empress Michiko, waves during the royal family's annual New Year's greeting to well-wishers gathered at the Imperial Palace in Tokyo on January 2, 2018.

Princess Mako of Akishino greets well-wishers from a balcony at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

Japanese Princess Mako arrives at the Imperial Palace in Tokyo on Jan. 2, 2018, where the imperial family offered New Year's greetings to well-wishers.

Crown Princess Masako is seen on arrival at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

Crown Princess Masako greets well-wishers from a balcony at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

Emperor Akihito (L foreground), Empress Michiko (R foreground) and other members of Japan's imperial family attend a New Year's ceremony at the Imperial Palace in Tokyo on Jan. 1, 2018.

Japanese Crown Prince Naruhito (L) and Crown Princess Masako arrive at the Imperial Palace in Tokyo on Jan. 2, 2018, to offer New Year's greetings to well-wishers.

Japanese Emperor Akihito (R) and Crown Prince Naruhito greet well-wishers gathered at the Imperial Palace in Tokyo on Jan. 2, 2018.

Empress Michiko greet well-wishers from a balcony at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

Japanese Emperor Akihito greet well-wishers from a balcony at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

Japanese Emperor Akihito delivered a speech (L) as Empress Michiko listens at the Imperial Palace in Tokyo on Jan. 2, 2018.

Japan's Emperor Akihito and Empress Michiko wave to well-wishers from the balcony of the Imperial Palace in Tokyo on January 2, 2018.

Princess Mako of Akishino greets well-wishers from a balcony at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

(L to R) Princess Ayako of Takamado, Princess Tsuguko of Takamado, Princess Hisako of Takamado, Crown Princess Masako, Crown Prince Naruhito, Emperor Akihito, Empress Michiko, Prince Akishino, Princess Kiko of Akishino, Princess Mako of Akishino, Princess Yuriko of Mikasa, Princess Nobuko of Mikasa and Princess Akiko of Mikasa greet well-wishers from a balcony at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

(L to R) Crown Prince Naruhito, Princess Aiko and Crown Princess Masako wave to media reporters on arrival at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

Prince Akishino and Princess Kiko of Akishino are seen on arrival at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

(L to R) Princess Mako of Akishino, Princess Yuriko of Mikasa and Princess Nobuko of Mikasa are seen at a balcony at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

(L to R) Prince Hisahito, Prince Akishino and Princess Kiko of Akishino are seen on arrival at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

(back-left) Prince Akishino and Princess Kiko of Akishino are seen on arrival at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

(L to R) Princess Mako of Akishino, Princess Yuriko of Mikasa, Princess Nobuko of Mikasa and Princess Akiko of Mikasa greet well-wishers from a balcony at the Imperial Palace on January 2, 2018 in Tokyo, Japan.

(center-L) Emperor Akihito of Japan and (center-R) Empress Michiko pose, on the occasion of New Year 2018, with their family: (2nd-L) Crown Prince Naruhito, his wife Princess Masako (L) and their daughter Princess Aiko (2nd row-L), Prince Fumihito of Akishino (2nd-R), his wife Princess Kiko (R)and their children Princess Mako (2nd row-R) and Prince Hisahito (2nd row-2nd-R) in Tokyo on December 31, 2017.

(L-R) Crown Princess Masako, with their daughter Princess Aiko, her husband Crown Prince Naruhito, in-laws Emperor Akihito of Japan, Empress Michiko of Japan, Prince Fumihito of Akishino, Princess Kiko, their children Princess Mako and Prince Hisahito pose, on the occasion of New Year 2018 in Tokyo on December 31, 2017.

Emperor Akihito of Japan at the Emperor of Japan's Vow Ceremony from the Imperial Palace in Tokyo on January 2, 2018.

Emperor Akihito of Japan delivered a speech at the Emperor of Japan's Vow Ceremony from the Imperial Palace in Tokyo on January 2, 2018. 02/01/2018 - Tokyo

Princess Mako of Akishino at the balcony of the Imperial Palace in Tokyo on January 2, 2018, her last appearance at the wishes of the imperial family, which she leaves in November 2018 due to her marriage with her companion Kei Komuro.

Princess Mako of Akishino at the official New Year's Eve ceremony at the Imperial Palace on January 1, 2018 in Tokyo. She was there for the last time before leaving the royal family in November 2018 because of her marriage to Kei Komuro.

Princess Kiko followed by her daughter Princess Mako of Akishino, Princess Nobuko of Mikasa, Princess Akiko of Mikasa and other women of the imperial family at the official New Year's greetings ceremony at the Imperial Palace on January 1, 2018 in Tokyo.

Emperor Akihito of Japan, his wife Empress Michiko and their son Crown Prince Naruhito at the official New Year's Eve ceremony at the Imperial Palace on January 1, 2018 in Tokyo.

Emperor Akihito of Japan and Empress Michiko during the official ceremony of New Year's greetings at the Imperial Palace on January 1, 2018 in Tokyo.