Updated at 7:45 a.m. ET on June 12

According to legend, Japan's monarchy originated 2,700 years ago with a direct descendant of the female goddess Amaterasu.

The current emperor, Akihito, is mortal. Expressing his wishes in oblique language last August, Akihito, 83, asked permission to abdicate, citing his advanced age and poor health.

On Friday, Japan's upper house of parliament approved a bill allowing Akihito to leave the Chrysanthemum Throne. Because the lower house approved the bill last week, it now becomes law.

It applies only to Akihito and only for three years.

The Japanese monarchy is the world's oldest. Akihito's father, Hirohito — Japan's wartime emperor — was the last to be considered divine. Hirohito died in 1989.

The New York Times reports:

"Emperor Akihito became enormously popular as he abandoned the aloof style of his father and sought to spend more time among the people. The Japanese revere him for his support of the pacifism enshrined in the nation's postwar Constitution, and his role as the nation's consoler in chief during natural disasters. Together with his wife, the Empress Michiko, he has traveled extensively, acting as an envoy of reconciliation with surrounding Asian countries that suffered during Japan's wartime aggression."

Peculiarities in Japanese custom and law have kept the royal family small. Succession runs through male members, and only men may serve as emperor.

When a female member of the royal family marries a commoner, she must leave the royal household. With only 19 current members of the royal family, marriage prospects for the women lie outside the household.

The Associated Press reports:

"The [Prime Minister Shinzo] Abe government avoided taking up divisive issues involving the status of female royals, which would have required a time-consuming and broader overhaul of the 1947 Imperial (Household) Law."To secure opposition support, the ruling party did agree to a non-binding attachment to the bill calling on the government to study ways to improve the status of princesses."That could include allowing them to keep their titles so that they can make up for the declining royal membership and continue to perform some royal family public duties."

Crown Prince Naruhito, 57, is next in line to the throne. He has one child, a daughter. Naruhito's younger brother, Prince Akishino, has two daughters and a 10-year-old son, Hisahito, the only grandchild eligible to serve as emperor.

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