Princess Mako has visited the mausoleums of her great grandparents in western Tokyo to report her upcoming marriage.
The eldest daughter of Crown Prince and Princess Akishino arrived at the Mausoleum of Emperor Showa on Tuesday morning.
The princess, wearing a long gray dress, offered a sacred sprig at the altar and bowed deeply.
She later visited the Mausoleum of Empress Kojun, the wife of Emperor Showa.
The Imperial Household Agency says the visits were not part of Imperial family customs but were held in accordance with Princess Mako's wishes.
The princess is set to marry former college classmate Komuro Kei on October 26.
Before then, she is expected to visit Emperor Naruhito and Empress Masako, as well as Emperor Emeritus Akihito and Empress Emerita Michiko, to bid farewell.
The princess will lose her Imperial status once she marries. She and Komuro are scheduled to hold a news conference on the day they tie the knot.