"The government will further consider [relevant steps] while respecting the supplementary resolution".
In addition to Princess Mako, there are six other unmarried princesses who could lose their imperial status if they marry commoners, raising the possibility that the royal family will soon not have enough members to carry out its public duties. A discussion about whether or not a woman would be able to ascend the throne was triggered in 2006 when the emperor had no grandsons, but was postponed after a boy was born to the imperial family. Female succession was strongly opposed by conservatives, and the plan was dropped after the wife of Naruhito's younger brother, Fumihito, gave birth to a son. However, the exact date of the Emperor's abdication is unknown.
Japanese media have reported that the likely timing of the abdication will be around the emperor's 85th birthday next year, in December.
Emperor Akihito made rare public remarks previous year saying his age may make fulfilling his duties more hard.
His words were widely interpreted as indicating his desire to relinquish the throne and the government entrusted an advisory panel to study the abdication issue the following month.
This will be the first Imperial abdication in about 200 years, since Emperor Kokaku stepped down in 1817. Japan's Cabinet approved the bill at the end of May.
Some scholars and politicians anxious that changing the law to allow any emperor to abdicate could put Japan's future monarchs at risk of being subject to political manipulation. The Japanese emperor has no real powers. As the Japan Times explained, there have been concerns in recent years that the royal family isn't producing enough male heirs to continue this bloodline, and Akihito's abdication has made those concerns all the more pertinent.
It applies only to Akihito and only for three years. Thus, Princess Aiko, the daughter of Crown Prince Naruhito, can not succeed her father.
While Akihito has two sons, only one of his four grandchildren, 10-year-old Prince Hisahito, is male. Accordingly, annual budget for Prince Akishino's private expenses will increase threefold to 91.5 million yen ($833,000). Akihito's father Hirohito - Japan's wartime emperor - was the last to be considered divine.
While on the throne, Emperor Akihito has often traveled with Empress Michiko to areas hit by natural disasters.
"It's so obvious that there are not enough imperial family members", said Keiko Hongo, a professor of medieval history at the University of Tokyo. Akihito's son, 57-year-old Crown Prince Naruhito, is next in line.