Japan's royal household says Emperor Akihito has been diagnosed with mild bronchial pneumonia and remains hospitalized for a 12th day.
The Imperial Household Agency said in a statement Friday that the emperor is responding to antibiotics. His fever climbed to near 39 degrees Celsius (102 degrees Fahrenheit) but is now falling.
The emperor, 77, developed a fever two weeks ago and was admitted into University of Tokyo Hospital on Nov. 6.
The emperor ascended the throne after his father Hirohito died in 1989.
His wife, Empress Michiko, remarked last month that staying healthy is an uphill battle for the popular royal couple. Akihito has been on hormone therapy since prostate surgery eight years ago. He also takes medication for his arteries.