Mako, the Emperor’s niece, was married to commoner and lawyer Kei Komuru in a ceremony without the formal rituals of a royal wedding.
Under Japanese law, female members of the imperial family lose their royal status upon marriage to a commoner but men do not.
Mako also turned down a payment offered to royal females upon their departure from the family. The couple, both 30, had endured a tumultuous four-year engagement, with Mako suffering from posttraumatic stress disorder triggered by criticism of her choice of groom.
The wedding was also postponed, allegedly while a money problem involving the groom’s mother was sorted out.
It is thought the couple will live in New York, where Kei works. He said: “I want to spend the only life I have with the one I love.”