Japan's Princess Mako waves from inside a car as she leaves her home for her marriage in Akasaka Estate in Tokyo, Japan October 26, 2021 in this photo taken by Kyodo. Kyodo/via REUTERS

Protesters hold banners during a march against the marriage between Japan's Princess Mako and her fiance Kei Komuro in Tokyo, Japan, October 26, 2021.

Protesters hold banners during a march against the marriage between Japan's Princess Mako and her fiance Kei Komuro in Tokyo, Japan, October 26, 2021.

Japan's Princess Mako (L), the daughter of Crown Prince Akishino and Crown Princess Kiko, talks with her younger sister Princess Kako as they stroll at the garden of their Akasaka imperial property residence in Tokyo, Japan October 6, 2021, ahead of her 30th birthday on October 23, 2021 and her marriage on October 26, 2021, in this handout photo provided by the Imperial Household Agency of Japan. Picture taken October 6, 2021. Mandatory credit Imperial Household Agency of Japan/Handout via REUTERS

Japan's Princess Mako hugs her sister Princess Kako and they are watched by her parents, Crown Prince Akishino and Crown Princess Kiko, before leaving her home for her marriage in Akasaka Estate in Tokyo, Japan October 26, 2021 in this photo taken by Kyodo. Kyodo/via REUTERS

Protesters hold banners during a march against the marriage between Japan's Princess Mako and her fiance Kei Komuro in Tokyo, Japan, October 26, 2021.

Japan's Princess Mako and her husband Kei Komuro attend a news conference to announce their marriage registration at Grand Arc Hotel in Tokyo, Japan, October 26, 2021. Nicolas Datiche/Pool via REUTERS

Protesters hold banners during a march against the marriage between Japan's Princess Mako and her fiance Kei Komuro in Tokyo, Japan, October 26, 2021. The slogan in the read reads, 'Bring back an imperial family where we can love and respect'.

Japan's Princess Mako and her husband Kei Komuro arrive for a news conference to announce their marriage registration at Grand Arc Hotel in Tokyo, Japan, October 26, 2021. Nicolas Datiche/Pool via REUTERS

Japan's Princess Mako and her husband Kei Komuro attend a news conference to announce their wedding at Grand Arc Hotel in Tokyo, Japan, October 26, 2021. Nicolas Datiche/Pool via REUTERS

Kei Komuro, the boyfriend of Japanese Princess Mako, arrives at Narita airport after a flight from New York, in Narita, east of Tokyo, Japan September 27, 2021, in this photo taken by Kyodo. Mandatory credit Kyodo/via REUTERS

Japan's Princess Mako, the eldest daughter of Crown Prince Akishino and Crown Princess Kiko, strolls at the garden of their Akasaka imperial property residence in Tokyo, Japan October 6, 2021, ahead of her 30th birthday on October 23, 2021 and her marriage on October 26, 2021, in this handout photo provided by the Imperial Household Agency of Japan. Picture taken October 6, 2021. Mandatory credit Imperial Household Agency of Japan/Handout via REUTERS

Japan's Princess Mako (not seen) and her husband Kei Komuro attend a news conference to announce their marriage registration at Grand Arc Hotel in Tokyo, Japan, October 26, 2021. Nicolas Datiche/Pool via REUTERS

Protesters hold banners during a march against the marriage between Japan's Princess Mako and her fiance Kei Komuro in Tokyo, Japan, October 26, 2021. REUTERS/Kim Kyung-Hoon

Protesters hold banners during a march against the marriage between Japan's Princess Mako and her fiance Kei Komuro in Tokyo, Japan, October 26, 2021.

Japan's Princess Mako, the daughter of Crown Prince Akishino and Crown Princess Kiko, walks towards the Three Palace Sanctuaries to pray ahead of her marriage at the Imperial Palace in Tokyo, Japan October 19, 2021, in this photo taken by Kyodo. Mandatory credit Kyodo/via REUTERS