The Cabinet on Friday approved a bill to let Emperor Akihito hand over the Chrysanthemum Throne to Crown Prince Naruhito in what would be Japan's first abdication in roughly 200 years.

The government is looking at December 2018, when the Emperor turns 85, as the timing for his abdication, which will likely trigger a change in Japan's gengo (era name), which remains in use throughout an emperor's reign, at the start of 2019, sources said.

The bill was specifically designed for Emperor Akihito, 83, to prevent other monarchs from easily following suit. Securing a stable succession process as the Imperial family shrinks remains a challenge. This issue was highlighted by news of Princess Mako's impending engagement to a commoner.