Akihito, 85, in a palace ritual Tuesday, will announce his retirement before other members of the royal family and top government officials. He was to perform private palace rituals to report his retirement to Shinto gods ahead of the official ceremony.
Akihito’s reign runs through midnight when his son Crown Prince Naruhito becomes new emperor and his era begins.
Akihito has devoted his career to make amends for the victims of a war fought in his father’s name, while bringing the aloof monarchy closer to the people.
Naruhito will ascend the Chrysanthemum throne in a separate ceremony on Wednesday.