When Japan’s Princess Ayako, the daughter of a cousin of Emperor Akihito, married a commoner last year,  she gave up her name, title and membership in the imperial family. In doing so, she subtracted one more member from the rapidly diminishing numbers of Japanese royals.

When another princess marries later this year, the royal line will shrink yet further. That means the pool of imperial family members will have declined from the current 18 to 17, with 13 of them female.

And that latter point is particularly important – for Japanese monarchs can, by law, only be males.

Aside from the two mentioned above, there are five unmarried princesses. Three are in their thirties; the only teenager among them is Princess Aiko, the 16-year-old daughter of the soon-to-be Emperor Naruhito and Empress Masako; the couple will ascend to the throne following the abdication of Emperor Akihito on 30 April. The emperor, who is 84, wants to turn his duties over to a younger royal.

Only one boy has been born into the Imperial family in the past 40 years. He is Prince Hisahito, now 11 – the only male of his generation. He is currently third in line to become Japan’s next emperor.

The latest royal wedding, between Princess Mako and her fiancé, Kei Komura, has been postponed so not to be overshadowed by the festivities surrounding the abdication of the current monarch and the enthronement of the new emperor the next day.

The imperial family has been greatly constrained by Japan’s marriage laws that say a bride enters her husband’s family and leaves her own family. Thus Princess Ayako of the Yamato dynasty became plain Mrs. Moriya on marriage.

By contrast, when thespian Megan Markle – a commoner, and an American to boot – married Prince Harry, she became a full-fledged member of the British royal family with her own title: The Duchess of Sussex.

Even so, there is no taboo preventing Japanese royal family members marrying commoners. Indeed, the current emperor and his son have both married commoners – who, as they had married male royals, assumed regal titles.

However, they could hardly have done otherwise since there is no Japanese aristocracy to provide potential mates.

One can thank the American occupiers of Japan for this state of affairs. After the conclusion of World War II, General Douglas MacArthur decided to keep the emperor to help maintain peace during the occupation, but abolished the Japanese aristocracy, save for some immediate family.

Strangely, given how the Americans encouraged emancipation of women in Japan, they left in place a law that restricts the monarchy to males only.

And marrying a commoner presents its own problems. Both Empress Michiko and the soon-to-be Empress Masako found it hard to adopt to imperial ways. Famously, Masako – who left a promising career as a diplomat to enter the palace – suffered something akin to a nervous breakdown, partly due to the pressure to conceive a male.

“They are challenged in many ways,” said one royal watcher, noting, for example, not just the public pressure to birth male heirs, but the stifling royal protocol.

Dire shortage

Still, for now, the succession seems secure – at least for the near future. Naruhito is only 58, so can reasonably be expected to reign for a good number of years to come. After him comes Prince Hisahito, the son of the emperor’s brother. However, due to the dire shortage of male heirs, there is no margin for error: Japan, unlike the UK, has no Prince Harry to step up to the throne if the situation demands it.

And it is safe to say there will be no more boys born into the family for a long time. Princess Kiko gave birth to Prince Hisahito at age 39 and probably won’t be getting pregnant again. Nor is Naruhito’s wife Masako likely to conceive again.

In 2005, when it looked like there might never be a suitable male heir to the throne, the government of then-Prime Minister Junichiro Koizumi reluctantly proposed legislation that would allow for a reigning empress (not just a consort.)

However, the proposed legislation was withdrawn quicker than you can say banzai with the birth of Prince Hisahito in 2006 – given the assurance that there were now sufficient males to carry the Yamato dynasty into at least the near future.

When a more liberal opposition party won power in 2008, then-Prime Minister Yoshihiko Noda reopened the matter of succession by allowing for an imperial house led by a female family member – such as Princess Ayako. But when Noda lost power to conservative Shinzo Abe, the matter was quietly dropped.

Female succession

Emperor Akihito re-opened the debate in 2016 when he announced that he wanted to abdicate in favor of his son and to retire from public life. That threw a spanner into the works: The possibility of an emperor’s abdication is not addressed in the Imperial House Law that governs imperial matters.

The government was willing to make a change to the law to accommodate the sitting monarch – but took great pains to explain that this was a one-off gesture to pave the way for the abdication, and nothing else.

Abe was afraid that if an open-ended debate got underway it would inevitably raise the issue of female succession to the throne – something that he and other conservatives in Japan oppose vehemently.

The new law passed in 2017 had an attached resolution, asking for the government to promptly come up with measures addressing the imperial family’s shrinking membership and report back to parliament.

So far, no report on this interesting matter has been forthcoming.

The option of creating royal households headed by women, which would allow female members to retain their royal status, has also been broached by the government. It is not uncommon elsewhere – look at Britain’s Queen Elizabeth II, for example. But this, too, is fiercely opposed by Japanese conservatives – of whom Abe is a member in good standing.

Under the American-written constitution, the emperor serves as a symbol of the state and the unity of the people and derives his authority from “the will of the people with whom resides sovereign power.” Yet, contrary to the conservative stance, public opinion polls consistently show that the public favors female succession.

There is another solution to the problem of the shrinking family. It has been suggested that male members descending from the old aristocracy, who were demoted to mere citizens during the American occupation, be brought into the imperial family as possible candidates for the throne.

In the unlikely event this plan were ever to be adopted, the scion of some Japanese living quietly as a commoner today could, feasibly, find himself the founder of an entirely new imperial dynasty.