Masahito, Prince Hitachi
Masahito, Prince Hitachi (born November 28, 1935) is a member of Japan’s Imperial Family. He is the younger brother of Emperor Emeritus Akihito and the uncle of Emperor Naruhito. He is the second son of Emperor Shōwa (Hirohito) and Empress Kōjun, and he is third and last in line to the Chrysanthemum Throne.
He is known for his charitable work and his research on cancer. He was born at the Tokyo Imperial Palace and was called Prince Yoshi as a child. He attended the Gakushuin Peers’ School and was evacuated to Nikko during World War II to escape bombing. After the war, he was tutored in English by Elizabeth Gray Vining.
He earned a chemistry degree from Gakushuin University in 1958 and did postgraduate work at Tokyo University. In 1969 he became a research associate at the Japanese Foundation for Cancer Research, studying how cells divide. His work has been published in cancer journals in Japan and the United States. He received honorary doctorates from George Washington University in 1997 and the University of Minnesota in 2001, and he became an honorary member of the German Association for Cancer Research in 1999.
On September 30, 1964, he married Hanako Tsugaru. The next day he was given the title Hitachi-no-miya and permission to form a new branch of the Imperial Family. They live in a palace near Shibuya. The couple have no children because he contracted polio as a child, which left him infertile.
In 2021, Japan discussed changing the Imperial Household Law to let him adopt a male heir from other imperial branches to help with succession.
Prince Hitachi is the honorary president of many charitable organizations, especially those promoting international exchange. The couple has traveled abroad for these duties, including visits to Nicaragua and El Salvador in 2005, France in 2007, and Peru in 2009.
Health updates: In February 2023 he had a fever and was hospitalized in March for ureteral stones, receiving treatment and being discharged later that month. He had a second procedure on March 21 and was discharged on March 24, then readmitted on April 2 with fever and loss of appetite due to a urinary tract infection and discharged on April 24.
This page was last edited on 2 February 2026, at 02:22 (CET).