Emperor Akihito will undergo surgery for prostate cancer on Jan. 18, the Imperial Household Agency said Wednesday.
The 69-year-old Emperor will be admitted to University of Tokyo Hospital on the morning of Jan. 16 to prepare for the operation. He is scheduled to remain hospitalized for about a month and will rest at the Imperial residence afterward, according to the agency.
Crown Prince Naruhito will take over his father's constitutional functions during his absence.
The agency added that it and the hospital will accept get-well cards and the signing of a visitors' book during the Emperor's hospitalization, but not flowers or presents.
Cancer cells were detected in a tissue sample taken from the Emperor's prostate in a biopsy in late December.
The cancer is a well-differentiated tumor and will not spread, the agency said, and the Emperor has a very good chance of a full recovery once the cancerous tissue is removed, according to the agency.
The Emperor was absent from part of the New Year's rites but greeted well-wishers at the Imperial Palace on Jan. 2 as scheduled.