Japan's Imperial Household Agency said Princess Ayako, 27, the third daughter of Princess Hisako and the late Prince Takamado, will marry a 32-year-old worker at a shipping firm in October.
She follows in the footsteps of Princess Mako, 26 - the eldest granddaughter of Emperor Akihito and Empress Michiko - who is set to become engaged to Mr Kei Kumuro.
Last month, Britain's Prince Harry also married a "commoner" - actress Meghan Markle - in a dazzling ceremony at St George's Chapel in Windsor Castle that was watched by a global TV audience of millions.
Which other royals are still on the market? The Straits Times casts an appreciative eye on the hottest eligible princes and princesses around the world.
PRINCE JOACHIM, 25
The third child of Lorenz, Archduke of Austria-Este, and Princess Astrid of Belgium
Not much is known about the rosy-cheeked Prince Joachim, who prefers to keep a low profile.
According to online reports, he studied at the Nautical School in Brugge to become an officer in the Belgian Navy and also has a degree in international economics, management and finance from Bocconi University in Milan.
Other than that, there are no details about his personal life, besides the rare sighting at official royal events such as his elder brother Prince Amedeo’s wedding in 2014 – where his date was his elder sister, Princess Maria Laura.
A noble man of mystery. We like.
LADY AMELIA WINDSOR, 22
Youngest of three children born to George Windsor, Earl of St Andrews, and Sylvana Tomaselli
She was crowned “the most beautiful member of the royal family” by Tatler UK magazine last year, and no wonder – just look at her big eyes and sultry lips. A fashion model signed to modelling agency Storm – which made Cara Delevigne and Kate Moss household names – she has graced the runway of big luxury brands such as Dolce & Gabbana as well as fronted magazine covers.
It seems that she is more interested in working behind the scenes in the fashion world though.
The University of Edinburgh student, who is studying French and Italian in Paris and Rome this year, was quoted in a January interview with Miss Vogue: “I would love to make a contribution to any aspect behind the creative process. On my year abroad, I want to really further my understanding of every aspect of a fashion house: from the making of the fabrics to the production of a catwalk show.”
PRINCESS SIRIVANNAVARI NARIRATANA, 30
The youngest of five children born to King Vajiralongkorn
Considered one of the most stylish royals around, this Thai princess regularly makes the best-dressed lists for stepping out in fashion-forward pieces.
But it is more than just about having a team of talented stylists at her beck and call – the 30-year-old, who studied fashion and textiles in the Faculty of Fine and Applied Arts at Chulalongkorn University, is very much into fashion design herself.
Over the years, she has launched different fashion collections under her label Sirivannavari, which is mostly made up of trendy modern apparel featuring traditional Thai accents and materials.
Beyond the fashion circuit, she is also an accomplished athlete in both badminton and equestrianism.
In 2005, she and her team-mates won a gold medal for the women’s team event in badminton at the Southeast Asian Games.
At the games in Kuala Lumpur last month, she and her team-mates took home a silver medal in the dressage team event, which she dedicated to her late grandfather, King Bhumibol Adulyadej.
CHARLOTTE MARIE POMELINE CASIRAGHI, 31
Second child of Caroline, Princess of Hanover, and Stefano Casiraghi
Her bloodline is all class and elegance – her grandmother, after all, was the inimitable American actress Grace Kelly.
She has preferred to stay out of the limelight, however, appearing in paparazzi photos only at official Monaco state events.
Still, Vanity Fair magazine put her on its International Best Dressed List in 2006, noting her penchant for bright colours, prints and florals.
She is especially interested in sustainable fashion, founding the Ever Manifesto in 2009, a publication described as a “sustainable fashion and design think-tank”. It is distributed at fashion events and stores.
Although she has a 3 1/2-year-old son named Raphael with stand-up comedian Gad Elmaleh, her child is not included in the line of succession to the throne as the couple never married, and split in 2015.
SHEIKH HAMDAN BIN MOHAMMED AL MAKTOUM, 34
Son of Mohammed bin Rashid Al Maktoum, the Vice-President and Prime Minister of the United Arab Emirates, and ruler of Dubai
Sheikh Hamdan was appointed the crown prince of Dubai by his father in 2008, even though he had an elder brother named Rashid at the time. Rashid died two years ago of a heart attack.
Besides his royal title, this handsome prince has a long list of other official appointments, such as chairman of the Dubai Executive Council, the Dubai Autism Centre and the Dubai Sports Council as well as president of the Hamdan Bin Mohammed Smart University.
But his 5.7 million Instagram (@faz3) followers are a lot more interested in his personal pursuits as displayed in his many photos, whether it is when he taps into his athletic side – he spends a lot of time hiking outdoors – or when he showers his love on horses and camels.
By the way, he is popularly known as Fazza, the pen name he uses to publish his poetry. Yes, he is a romantic too.
PRINCE ABDUL MATEEN OF BRUNEI, 26
The 10th child of Hassanal Bolkiah, Sultan of Brunei
Prince Mateen got the loudest screams at the Southeast Asian Games in Kuala Lumpur, where he represented his country in equestrian polo events – and it has nothing to do with any fancy horse tricks.
Rather, women were going gaga over his boyish good looks, marked by those intense eyebrows and sharp jawline.
According to his Instagram account (@tmski), which has more than 634,000 followers, he loves travelling – he can fly his own plane – is a cat person and plays the guitar.
He is smart too, with a bachelor’s degree in international politics from King’s College London, before graduating with a master’s degree in international studies and diplomacy from the School Of Oriental and African Studies, University of London.
He is reportedly single, but is on the look-out for a future princess. In an interview with GQ Thailand last year, he said that his ideal girl would have to be “someone who is genuine and real, someone who is very simple”.
Go get him, girls.
HUSSEIN BIN ABDULLAH, CROWN PRINCE, 23
Eldest child of King Abdullah II and Queen Rania
His mother is Queen Rania, who is known for her advocacy of everything from education to community empowerment, and her social activism has rubbed off on her son, who is active in youth empowerment efforts.
He founded the Haqiq Initiative, which is described as a “national leadership programme which aims to enhance, develop, enrich and help youth reach their full potential as productive leaders and caring citizens”.
The Georgetown University graduate also started a National Aeronautics and Space Administration internship programme, which gives Jordanian youth the opportunity of work experience at the American institution, as well as the Hearing Without Borders initiative, which provides rehabilitation to hearing impaired children.
Two years ago, he became the youngest person to chair a United Nations Security Council meeting, which was an open debate on the role of youth in countering violent extremism. After the meeting, then United Nations Secretary-General Ban Ki Moon praised the prince: “He is not yet 21 years old, but he is already a leader in the 21st century.”
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