Empress emerita Michiko, who turns 90 on Oct 20, left hospital Sunday after having surgery for a broken thigh, local media reported.
Michiko, the mother of Emperor Naruhito, fell on October 6 at her Tokyo residence and was admitted to hospital the next day after doctors diagnosed a fracture of the right femur.
She left hospital Sunday afternoon, local media said.
Officials at Imperial Household Agency could not be reached for comment, but an official previously told AFP that her treatment had been successful.
Michiko and her husband -- Emperor emeritus Akihito, 90 -- are credited with modernising the tradition-bound monarchy and bringing it closer to the public.
The first commoner to marry an imperial heir in Japan, Michiko gave birth to Naruhito in 1960. Her second son, Prince Akishino, was born in 1965.
In 2019, Akihito, at the age of 85, became Japan's first monarch to abdicate in two centuries.
