Prince Katsura, a cousin of Japanese Emperor Akihito, died yesterday in Tokyo of heart failure after years of ill health, the palace said. He was 66 and had fought against a string of illnesses in recent years.
As the second son of Prince Mikasa, a 98-year-old uncle of the Emperor, Prince Katsura had been sixth in line to the throne. The death of the prince, who was not married and had no children, brings an end to his household.
Prime Minister Shinzo Abe released a statement saying: "I cannot help but be saddened by His Royal Highness Prince Katsura's death."
Abe said the prince had made contributions in various fields, including agriculture and traditional crafts, and played a major role in building international goodwill, for instance by heading the Japan Australia New Zealand Society, an association dedicated to deepening the friendship among the three countries.
His death is the first of an Imperial family member since June 2012, when Prince Tomohito of Mikasa, the prince's elder brother, died at age 66 after a long battle with cancer.
Born on February 11, 1948, Prince Katsura graduated from Gakushuin University in 1971 and pursued his studies at a graduate school of the Australian National University.
After returning to Japan, he worked part-time at broadcaster NHK from 1974 to 1985.
Kyodo, Agence France-Presse