In the rare video message released to the public last August, Emperor Akihito cited concerns that his age and declining health may one day stop him from fulfilling his duties. This announcement had surprised the nation. Crown Prince Naruhito's heir will be his younger brother, Prince Fumihito followed by Prince Hisahito. The government will carefully make decisions that consider the possible effects on people's lives.
The abdication, the first since 1817, appears to have support among the general population, who view it as a sign of changing times.
Although there was disagreement on how the Bill should be drafted, but the opposition Democratic Party (DP) favoured a permanent revision. The titles for the Emperor and Empress after the abdication will be "joko" and "jokogo".
Japan's Prince Hisahito, wearing a traditional ceremonial attire, with his parents, Prince Akishino, Princess Kiko, his sisters Princess Mako, left, and Princess Kako, right, after attending "Chakko-no-gi" ceremony to celebrate his passage from infancy to childhood in 2011.
The emperor and his wife Empress Michiko are seen as being the more accessible face of a monarchy that largely remains in the shadows, unlike the British royals. But, it is reportedly on side with the current one-off bill after talks with the ruling bloc.
The unexpected move presented a challenge since there was no law to deal with an emperor retiring from what is usually a job for life.
The topic has garnered some criticism and many are questioning whether Mr Abe will reform the Imperial succession system to allow female members of the royal family to ascend to the throne.
Another issue the Japanese government will discuss is the continuity of the heirs, as women are not allowed to inherit the throne. Only male members are allowed to become emperor.
Females can not ascend to the throne and must leave the imperial family when they marry commoners, according to the 1947 Imperial House Law, which stipulates imperial matters.
The Emperor's Birthday holiday on December 23 will be changed to February 23, the birthday of Crown Prince Naruhito, said the legislation.
Read: Who Is Princess Mako? "The creation of female-led imperial branches ... can no longer be put off", the legislation states.
Discussions over whether to allow females to reign is once again surfacing, which would ease the imperial family's crisis. Out of those 13 are women and eight are below 40 years old.
The other seven unmarried children are all women, and six of them are in their 20s and 30s.
The government will now begin the process of arranging his abdication, expected to happen in late 2018, and the handover to Crown Prince Naruhito.