In remarks to reporters, Mr. Abe’s chief cabinet secretary, Yoshihide Suga, declined to comment on the timing of the abdication, although Kyodo News reported that December 2018 was a target.
Any decision regarding the emperor is freighted in Japan, where until World War II, he was seen as a god. The postwar Constitution, written by American occupiers, stripped the emperor of his status as a deity and set him up instead as a symbol of Japanese unity.
Emperor Akihito has also come to represent the pacifism enshrined in the Constitution and has acted as the country’s emissary of historic reconciliation with surrounding Asian countries that suffered under Japan’s aggression during the war. He has also visited regions in Japan that have been ravaged by disaster, most famously going on television to console the nation after the 2011 earthquake and tsunami.
While the Japanese public overwhelmingly supports allowing the emperor to retire, conservative supporters of Mr. Abe have made clear that they do not want the government to set a precedent by permanently altering the Imperial Household Law, which governs succession.
Conservatives are loath to open the law to a more sweeping overhaul because they fear that doing so would lead to a change to admit women as rightful heirs to the throne.
The bill approved by the cabinet on Friday makes no mention of female heirs to the throne. Prince Naruhito’s only child is a daughter, Princess Aiko, 15, so his successor would be his brother, Prince Akishino, followed by Prince Akishino’s son, Hisahito, 10.
Yet in repeated polls, a vast majority of Japanese have said they support a woman ascending to the throne. Without such a change, the royal family faces a looming succession crisis, as there are only five male heirs left in the family, and when women marry, they are forced to leave the imperial household.
The upcoming engagement of Princess Mako, 25, the emperor’s eldest granddaughter, highlights the limitations of the Imperial Household Law. Because she plans to marry a commoner, she will have to leave the royal family, and even if she were to bear a son, he would not be in line to the throne. The imperial law not only bars women from reigning, but also insists that succession pass only through men of the royal family.
Critics say the law is outdated and should be changed to modernize Japan’s royal family. The law is “anachronistic and ridiculous, in terms of gender and class,” said Gill Steel, an associate professor at Doshisha University in Kyoto, Japan. “Even the imperial family, and the politicians responsible for the law, need to move into the 21st century.”
The opposition Democratic Party said that during the parliamentary debate on the bill, it would call for a supplementary clause allowing women to remain in the royal family even after marriage.
The legislation approved Friday would give the emperor and his wife, Empress Michiko, new titles upon abdication. They would be known as joko and jokogo. The bill would also switch the annual holiday commemorating the emperor’s birthday from Emperor Akihito’s birthday in December to his son’s in February.