Tokyo (CNN) Japan's Princess Mako is giving up her royal status -- all in the name of love.

The groom-to-be is a prince himself ... of sorts.

The Imperial Household tells CNN plans are underway for the 25-year-old princess, granddaughter of Emperor Akihito, to become engaged to Kei Komuro, also 25, a law firm worker and graduate student who once starred in a tourism campaign as "Prince of the Sea."

The couple met five years ago as students at the International Christian University in Tokyo, Japan's national broadcaster NHK reported.

It was while in university that Komuro played the "Prince of the Sea" in a beach tourism campaign for the city of Fujisawa, south of Tokyo.

Kei Komuro, center, is interviewed by reporters in Tokyo Wednesday, May 17 2017.

Shrinking imperial family

Japan's centuries-old imperial law requires a princess to leave the imperial family upon marriage to a commoner.

The last to do so was Princess Mako's aunt, Sayako, the only daughter of Emperor Akhito, when she married town planner Yoshiki Kuroda in 2005.

The engagement won't become official until a ceremonial exchange of gifts, but the news has reignited concerns about the shrinking size of the imperial family, which currently has 19 members, 14 of whom are female.

Imperial law only allows the throne to be passed to male heirs, of which there are only three: Crown Prince Naruhito, his younger brother Crown Prince Akishino, and Akishino's son, Prince Hisahito.

In addition to Princess Mako, there are six other unmarried princesses -- who will also lose their royal status if they marry commoners. That has raised the possibility that the imperial family will not have enough members to continue carrying out its public duties.

Future of the monarchy

Last summer, 83-year-old Emperor Akihito voiced concerns that his advanced age may begin to affect his ability to rule.

Akihito said that while he felt he was in good health he was worried about the increasing burden of the role.

"When I consider that my fitness level is gradually declining, I am worried that it may become difficult for me to carry out my duties as the symbol of the State with my whole being as I have done until now," he said.

Photos: Photos: Japan's Emperor Akihito Japanese Emperor Akihito turned 84 on December 23, 2017. Akihito is the 125th Emperor of Japan, a direct descendant of Japan's first emperor Jimmu, circa 660 B.C. Here, we take a look at the life of the world's only monarch with the title of emperor. Hide Caption 1 of 23 Photos: Photos: Japan's Emperor Akihito A portrait of Crown Prince Akihito in January 1936 at age 3. He is the son of Empress Nagako and Emperor Hirohito, whom he succeeded in 1989. The Chrysanthemum Throne is the oldest hereditary monarchy in the world. Records show the imperial line to be unbroken for 14 centuries. Hide Caption 2 of 23 Photos: Photos: Japan's Emperor Akihito Crown Prince Akihito with some of his school friends at the Imperial School in Tokyo, circa 1938. Hide Caption 3 of 23 Photos: Photos: Japan's Emperor Akihito Crown Prince Akihito in ceremonial robes for his formal investiture as crown prince at the Tokyo Imperial Palace on November 10, 1952. Hide Caption 4 of 23 Photos: Photos: Japan's Emperor Akihito Prince Akihito in his private study at the Imperial Palace in 1952. Hide Caption 5 of 23 Photos: Photos: Japan's Emperor Akihito Queen Elizabeth II and Akihito are seen in the royal box at the Epsom Downs Racecourse on June 6, 1953, in England. Crown Prince Akihito made the trip to attend her coronation. Hide Caption 6 of 23 Photos: Photos: Japan's Emperor Akihito Akihito addresses the crowd upon arrival at Oahu Airport on October 8, 1953, in Honolulu. During seven months of travel, the crown prince visited 14 countries. Hide Caption 7 of 23 Photos: Photos: Japan's Emperor Akihito Akihito during his wedding to Michiko Shoda in 1959. He is the first Japanese crown prince to marry a commoner. Hide Caption 8 of 23 Photos: Photos: Japan's Emperor Akihito Akihito with his pet dog Dingo in December 1963, on the grounds of Togu Palace, his residence in Tokyo. Hide Caption 9 of 23 Photos: Photos: Japan's Emperor Akihito Prince Akihito takes a walk with Princess Michiko and their son Naruhito in 1964. Hide Caption 10 of 23 Photos: Photos: Japan's Emperor Akihito In a 1969 portrait, Emperor Hirohito and Empress Nagako pose with their children and grandchildren. Crown Prince Akihito stands on the far right. Hide Caption 11 of 23 Photos: Photos: Japan's Emperor Akihito Visitors to China's Forbidden City walk beneath Japanese and Chinese flags, flown to welcome Emperor Akihito on October 23,1992. Akihito's visit to China was the first ever by a Japanese emperor. Hide Caption 12 of 23 Photos: Photos: Japan's Emperor Akihito President Bill Clinton offers a toast to Emperor Akihito at the White House in June 1994, during the first state dinner of Clinton's administration. Hide Caption 13 of 23 Photos: Photos: Japan's Emperor Akihito South African President Nelson Mandela and Emperor Akihito toast during a banquet at the Imperial Palace in Tokyo in July 1995. Hide Caption 14 of 23 Photos: Photos: Japan's Emperor Akihito Emperor Akihito leaves the Imperial Palace for the hospital in January 2003. The emperor had a successful operation to remove his cancerous prostate. Hide Caption 15 of 23 Photos: Photos: Japan's Emperor Akihito Emperor Akihito and Empress Michiko leave the residence of the late Princess Kikuko after paying their respects in Tokyo on December 19, 2004. The princess was Akihito's aunt. Hide Caption 16 of 23 Photos: Photos: Japan's Emperor Akihito Akihito's eldest son and heir-apparent, Crown Prince Naruhito, granddaughter Princess Aiko, and Crown Princess Masako enter the Imperial Palace in Tokyo on September 2, 2006. Hide Caption 17 of 23 Photos: Photos: Japan's Emperor Akihito The Emperor and the Empress greet U.S. President Barack Obama at the Imperial Palace on November 14, 2009. Hide Caption 18 of 23 Photos: Photos: Japan's Emperor Akihito Akihito leaves the University of Tokyo Hospital in Tokyo on February 12, 2012. Akihito was scheduled to undergo heart bypass surgery after tests showed the narrowing of his arteries had worsened. Hide Caption 19 of 23 Photos: Photos: Japan's Emperor Akihito Emperor Akihito and Empress Michiko are greeted at Chennai International Airport in India on December 4, 2013, after arriving from New Delhi on the second leg of their weeklong trip to India. This was the first time they had been to India in 53 years. Hide Caption 20 of 23 Photos: Photos: Japan's Emperor Akihito From the balcony of the Imperial Palace, Emperor Akihito greets thousands of people, waving Japanese flags, who have gathered to wish him a happy 82nd birthday on December 23, 2014. Hide Caption 21 of 23 Photos: Photos: Japan's Emperor Akihito Then Philippine President, Benigno Aquino welcomes Emperor Akihito and Empress Michiko as they start their 5-day state visit to the Philippines on January 26, 2016. A gesture to honor 60 years of strong diplomacy post-WWII, their trip marked the first-ever visit by a reigning Japanese emperor to the Philippines. Hide Caption 22 of 23 Photos: Photos: Japan's Emperor Akihito Emperor Akihito and Empress Michiko wave to well-wishers from the balcony of the Imperial Palace in Tokyo on January 2, 2018. Hide Caption 23 of 23

His announcement followed one from the Imperial Household a few months earlier that he and Empress Michiko, 82, would reduce their public appearances.

Imperial law requires an Emperor to serve for life, but Akihito's announcement put plans into motion for the Japanese parliament to allow the Emperor to step aside should he choose to. The draft bill for the Emperor's abdication is to be submitted for both the upper and lower houses of parliament this week.

'Prince of the Sea'

On Wednesday, Japanese media focused on the man who has stolen Princess Mako's heart.

Journalists camped out in front of the law offices where Kei Komuro works as a paralegal.

Komuro declined to answer questions about the impending engagement, telling reporters, "I would like to talk about it when the time comes."

Japanese citizens also wanted to find out more about Komuro, flooding the Fujisawa City Ocean Prince website, local media reported.

Reactions from the public have so far been generally positive, but some are wondering what the upcoming marriage will mean for the future of the monarchy.

"I personally think a female imperial member should be allowed (to remain in the family)," said Meiko Hirayama, a 44-year-old employee at an accounting firm. "I guess the male line of succession would be kept through the crown prince and his brother, but I think there should be no problem that there could be a female emperor someday."

But 71-year-old Katsuiji Tsunoda insisted the heir to the throne exclusively be male.

"It's a tradition that has continued for over a thousand years. If we go with the global trend, anyone could be the emperor," he told CNN. "We must respect tradition."