Crown Prince Naruhito expected to succeed 83-year-old Emperor Akihito when he retires next year
The bill will be sent to the parliament for approval before it can enter into force, while the actual abdication is expected to take place on January 1, 2019.
In a rare televised address to the nation last August, the emperor, who has had health issues such as prostate cancer, indicated that at 83, he was not sure he would be able to continue to perform his duties for much longer.
Under the current Imperial Household Law, there is no provision permitting the emperor to abdicate. This is true even though before the modern era, it was common for emperors to retire although they often wielded power from behind the scenes.
The new law, however, applies only to the sitting monarch and does not address the issue of future emperors. The conservative government of Prime Minister Shinzo Abe is reluctant to open the imperial system to wide-ranging debate.
Traditionalists fear that fully ventilating issues surrounding the emperor system might open the way to permitting a woman to assume the throne as a reigning empress.
The Constitution defines the emperor as a "symbol of state and the unity of the Japanese people". His duties, though possibly onerous for a man in his 80s, are by law very limited.