Why has wedding of Japan's Princess Mako still not gone ahead?

They have been together since university, their emotional bond apparently stronger than ever despite being separated by an ocean and a continent. And they have the blessing of a likely future emperor.

But for Japan’s Princess Mako – the eldest daughter of the first in line to the Chrysanthemum throne – and her boyfriend, Kei Komuro, the sound of wedding bells has grown more distant in the three years since they made their relationship public.

The couple are no closer to exchanging vows after their plans to marry two years ago were derailed by revelations that the would-be groom’s mother was embroiled in a financial dispute. The saga has not only fuelled unusually intrusive media and public interest in the private lives of Japan’s royals; it has also brought the country’s succession crisis into sharp relief.

Japan celebrated when, in May 2017, Mako and Komuro, a contemporary at International Christian University in Tokyo who does not come from a royal background, said they planned to get engaged later in the year and marry in November 2018. But in February 2018, the imperial household agency said the wedding had been put off for two years following reports that Komuro’s mother owed money, including education fees for her son, to an ex-fiance. A date for the wedding has yet to be set.

This week, Mako’s father, Crown Prince Akishino, gave the marriage his blessing but suggested that the couple, who are both 29, had yet to win over a sceptical Japanese public, who will foot the bill for a lump sum Mako will receive when she marries and leaves the imperial household.

“I approve of them getting married,” he said in comments to journalists ahead of his 55th birthday on Monday. “The constitution says that marriage shall be based only on the mutual consent of both sexes. I believe I, as a parent, should respect their intentions if marriage is what they truly want.”

But, he added, Komuro’s family needed to make a “visible” response to his mother’s financial troubles, which, according to Japanese media, have not been resolved two years after they were revealed by a weekly magazine.

Akishino, who became crown prince after his elder brother, Naruhito, ascended the throne last year, was quoted by the Kyodo news agency as saying: “From my point of view, I don’t think they are in a situation in which many people are convinced and pleased [about their proposed marriage]” – adding that Mako was aware that the public was not fully behind the union.

When Mako marries, she will immediately lose her royal status and, like the previous emperor’s daughter, Sayako Kuroda, live a comparatively “ordinary” life with her commoner husband beyond the walls of the imperial palace in Tokyo.

The family she leaves behind will shrink again. As the Asahi Shimbun newspaper has pointed out, only seven members of the imperial family are below 40, and all but one of them are women. Under Japan’s succession laws, no female member of the imperial family – not even the emperor’s 19-year-old daughter, Aiko – can become a reigning monarch.

No Japanese administration has shown an appetite for revising the 1947 succession law since the maverick conservative, Junichiro Koizumi, saw his reform plans fizzle out after the 2006 birth of Prince Hisahito, Mako’s younger brother and the first male to be born into the imperial family for 40 years.

While the birth of Hisahito, who is second in line to the throne, gave the family a one-generation reprieve, if he does not go on to have a son an imperial line some believe stretches back 2,500 years will come to an end.

A potential constitutional crisis will be furthest from the thoughts of Mako and Komuro, who is studying for a law degree at Fordham University in New York, as they consider their next move, including a suggestion by her father that they offer the public an explanation once they have agreed on a wedding date.

The two consider each other “irreplaceable”, the princess said recently, adding that they thought of each other as “someone to rely on, during both happy times and unhappy times”.