TOKYO — When Japanese Princess Mako announced her engagement to college sweetheart Kei Komuro at a 2017 news conference, the couple giggled as they recounted the story of how they fell in love.

On Tuesday, at their first public appearance since, the couple sat at arm’s length and somberly read a joint statement explaining why they had registered their marriage earlier in the day. It was a stark reminder of how much public sentiment has soured over the past four years.

Although their engagement was initially celebrated in Japan, it quickly became divisive when news surfaced about a financial dispute involving Komuro’s mother. Despite it all, the couple stood firm, glancing knowingly at each other Tuesday as they addressed the public following disparagement ranging from questioning of their integrity to complaints about Komuro’s looks.

“Kei is an irreplaceable person for me. And for the two of us, marriage was a necessary decision in our lives to protect our hearts,” Mako said.

“I love Mako,” Komuro said. “I would like to spend my one and only life with the person I love.”

To marry a commoner, the princess was required to abdicate her royal status. Addressing the public as Mako Komuro, rather than Princess Mako, she apologized to those who disagreed with their nuptials and thanked those who supported them.

She also expressed appreciation for her now-husband and the public criticism he has faced — a rare expression of private feelings about the public perception of a member of the royal family, experts said.

“I am thankful that despite harsh public criticism, Kei continued to hold on to his feelings to marry me. If he had given up on the marriage, he wouldn’t have had to face years of relentless hate,” she said.

The couple, both 30, have faced a torrent of criticism online depicting Komuro as unfit for the princess. Protesters gathered to oppose their marriage, including on their wedding day. Mako has been experiencing symptoms of post-traumatic stress disorder in the face of the public rancor, according to her doctor.

In the end, there was no extravagant wedding ceremony. A staff member of the Imperial Housing Agency submitted their paperwork at the registry office. As Mako left her family estate in Akasaka, a district of Tokyo, Mako bowed to her parents and her sister, Princess Kako, who gave her a big hug.

The couple’s plight has drawn attention to the Japanese imperial family’s succession crisis and the laws that alienate its female members.

Women have no path to the throne, and they are barred from marrying outside the royal family. Men are not subject to this restriction. The women who exit the family cannot return, even if they get a divorce, and their male children lose their chance at reigning. There is now just one heir to the throne, Prince Hisahito, who is Mako’s brother.

“Criticism has always been centered on women imperial family members who don’t even have the right to succession,” said Hideya Kawanishi, an associate professor at Nagoya University who specializes in Japanese history and the imperial family system. “Unfortunately, I think there is a certain misogynistic aspect to the Japanese imperial family.”

Japanese society in general has been characterized by a high degree of discrimination against women, with the World Economic Forum putting it 120 out of 156 countries for gender equality — the worst ranking for a major developed nation. The resignation of the octogenarian head of Olympic Committee after making demeaning remarks about women this year shed further light on sexism in the country.

Mako has set a new bar for imperial family members by bucking historical constraints, said Akinori Takamori, an expert on imperial family at the Kokugakuin University in Tokyo.

“A member of the imperial family has set a precedent by overcoming various obstacles, while following through with her true feelings and beliefs, which will have a positive effect for the imperial family as they continue on in a new age — hopefully, in a more healthy form,” he said.

Mako has declined the $1.35 million taxpayer gift intended to soften the blow of abdicating her title — becoming the first in Japan’s royal family to reject the payment. The couple also announced that they would pay for Tuesday’s news conference.

The couple now plans to move to the United States and may live in New York, where Komuro practices law. The former princess is a certified art curator and holds a master’s degree in art museum and gallery studies.

They declined to answer questions about their future. The former princess said she hoped to “have a warm household and live peacefully.”