Prince Akishino, who turns 46 on Wednesday, has said it will become necessary to hold a public debate on whether an age limit is needed for emperors, who currently serve for life.
The youngest son of Emperor Akihito and Empress Michiko made the remark at a news conference he held together with his wife, Princess Kiko, 45, ahead of his birthday.
The 77-year-old Emperor resumed his official duties Tuesday after being hospitalized for 19 days this month for bronchial pneumonia.