Akihito, 83, who has had heart surgery and treatment for prostate cancer, said past year he feared age might make it hard for him to continue to fulfill his duties, Reuters reported. The law-which will apply to Akihito alone, not any successors-calls for him to be replaced on the Chrysanthemum Throne within three years by his son, Crown Prince Naruhito, who is now 57 years old. The conservative government of Prime Minister Shinzo Abe was reluctant to make broader changes to centuries-old traditions by allowing any emperor to abdicate.
The Japanese Parliament has opened the door to modernising the Chrysanthemum Throne, unanimously passing a special law allowing the ailing Emperor Akihito to retire, and proposing that the government consider letting the royal bloodline pass through the women of the imperial family.
Only women are forced to renounce their royal status when they marry a commoner, heating up debate for members of the royal family such as Princess Mako.
The timing of the abdication, according to the law, will be decided under a government ordinance within three years of the law's promulgation after consulting with the Imperial House Council.
According to the 1947 Imperial House Law, females can not ascend to the throne and must leave the imperial family when they marry commoners. The first emperors, who are believed by many in Japan to have been the descendants of the sun goddess Amaterasu, have only mythical records.
"I think the reason people raise questions as to why women have to leave the royal household when they get married is because Japan is facing a succession crisis", says Jeff Kingston, director of Asian studies at Temple University Japan. Following the recent enactment of the special law, collaborative work between the Imperial Family and the public will continue.
Female imperial family members lose their royal status upon marriage to a commoner, a point highlighted by recent news that one of Akihito's granddaughters, Princess Mako, plans to marry her college sweetheart. That's because Crown Prince Naruhito has a daughter.
Some scholars and politicians have also argued that changing the law to allow any emperor to abdicate would risk Japan's monarchs becoming subject to political manipulation.
Akihito's abdication has rekindled concerns about a shortage of heirs.