is a member of the

Imperial House of Japan The is the reigning dynasty of Japan, consisting of those members of the extended family of the reigning emperor of Japan who undertake official and public duties. Under the present constitution of Japan, the emperor is "the symbol of the State ...

, the younger brother of Emperor emeritus Akihito and the paternal uncle of Emperor Naruhito. He is the second son and sixth born child of Emperor Shōwa and

Empress Kōjun Nagako (6 March 190316 June 2000), posthumously honoured as Empress Kōjun, was a member of the Imperial House of Japan, the wife of Emperor Shōwa (Hirohito) and the mother of Emperor Emeritus Akihito. She was Empress of Japan from 1926 unti ...

and is third and last in line to the

Chrysanthemum Throne The is the throne of the Emperor of Japan. The term also can refer to very specific seating, such as the throne in the Shishin-den at Kyoto Imperial Palace. Various other thrones or seats that are used by the Emperor during official functions ...

. He is mainly known for philanthropic activities and his research on the causes of cancer.

Early life and education

Prince Masahito and Princess Takako 1952-12

Born at

Tokyo Imperial Palace is the main residence of the Emperor of Japan. It is a large park-like area located in the Chiyoda, Chiyoda, Tokyo, Chiyoda district of the Chiyoda, Tokyo, Chiyoda ward of Tokyo and contains several buildings including the where the Emperor h ...

Tokyo Tokyo, officially the Tokyo Metropolis, is the capital of Japan, capital and List of cities in Japan, most populous city in Japan. With a population of over 14 million in the city proper in 2023, it is List of largest cities, one of the most ...

, Masahito held the childhood appellation . Masahito received his primary and secondary schooling at the Gakushūin Peers' School. In late 1944, the

Imperial Household Ministry The (IHA) is an agency of the government of Japan in charge of state matters concerning the Imperial Family, and the keeping of the Privy Seal and State Seal of Japan. From around the 8th century AD until the Second World War, it was known ...

evacuated Prince Yoshi and the Crown Prince to

Nikkō is a Cities of Japan, city in Tochigi Prefecture, Japan. , the city's population was 80,239, in 36,531 households. The population density was 55 persons per km2. The total area of the city is . Nikkō is a popular destination for Japanese and ...

, to escape the American

bombing of Tokyo The was a series of air raids on Japan by the United States Army Air Forces (USAAF), primarily launched during the closing campaigns of the Pacific War, Pacific Theatre of World War II in 1944–1945, prior to the atomic bombings of Hiroshima ...

. After the war, from 1947 to 1950, Mrs. Elizabeth Gray Vining tutored both princes and their sisters, the Princesses Kazuko, Atsuko, and Takako, in the English language. Her account of the experience is entitled ''Windows for the Crown Prince'' (1952). Prince Yoshi received his undergraduate degree in chemistry from the Faculty of Science at

Gakushuin University is a private university in Mejiro, Toshima, Tokyo. The Gakushūin (or "Peers School") was established during the Meiji period to educate the children of the Japanese nobility, but back then the institution had only the primary and secondary ...

in 1958. He subsequently did postgraduate work in the Faculty of Science at

Tokyo University The University of Tokyo (, abbreviated as in Japanese and UTokyo in English) is a public research university in Bunkyō, Tokyo, Japan. Founded in 1877 as the nation's first modern university by the merger of several pre-westernisation era ins ...

. In 1969, he became a Research Associate of the Japanese Foundation for Cancer Research specializing in the study of cellular division. The results of his research have been reported in the technical journals of the Japanese Cancer Association, as well as of the American Association for Cancer Research. In 1997, Prince Hitachi received an

honorary doctorate An honorary degree is an academic degree for which a university (or other degree-awarding institution) has waived all of the usual requirements. It is also known by the Latin phrases ''honoris causa'' ("for the sake of the honour") or '' ad hon ...

from

George Washington University The George Washington University (GW or GWU) is a Private university, private University charter#Federal, federally-chartered research university in Washington, D.C., United States. Originally named Columbian College, it was chartered in 1821 by ...

in the United States, and in April 2001 received another from the

University of Minnesota The University of Minnesota Twin Cities (historically known as University of Minnesota) is a public university, public Land-grant university, land-grant research university in the Minneapolis–Saint Paul, Twin Cities of Minneapolis and Saint ...

. In March 1999, he became an honorary member of the German Association for Cancer Research, in recognition of his significant scientific contributions to the field of cancer research.

Marriage

On 30 September 1964, the Prince married Hanako Tsugaru (born 19 July 1940), fourth daughter of the late Yoshitaka Tsugaru, a former

count Count (feminine: countess) is a historical title of nobility in certain European countries, varying in relative status, generally of middling rank in the hierarchy of nobility. Pine, L. G. ''Titles: How the King Became His Majesty''. New York: ...

and a descendant of the

daimyō were powerful Japanese magnates, feudal lords who, from the 10th century to the early Meiji era, Meiji period in the middle 19th century, ruled most of Japan from their vast hereditary land holdings. They were subordinate to the shogun and no ...

of Tsugaru Domain. The following day, Emperor Shōwa granted him the title ''Hitachi-no-miya'' (Prince Hitachi), and authorization to start a new branch of the Imperial Family in celebration of his wedding. Prince and Princess Hitachi have their official residence in a palace in large gardens off Komazawadori in Higashi, Shibuya. They have no children as the prince contracted polio as a child. He survived but became infertile as a result. In September 2021, the Japanese government considered plans to amend the Imperial Household Law and allow Prince Hitachi to adopt a male member of the former

shinnōke was the collective name for the four cadet branches of the Imperial House of Japan, which were until 1947 entitled to provide a successor to the Chrysanthemum Throne if the main line failed to produce an heir. The heads of these royal house ...

ōke The were branches of the Imperial House of Japan, Japanese imperial family (皇族 ''Kōka'') created from branches of the Fushimi-no-miya house, the last surviving ''Shinnōke'' cadet branch. All but two (the Kan'in-no-miya and Nashimoto-no-m ...

collateral branches of the imperial family in an effort to address the

Japanese imperial succession debate From 2001 to 2006, Japan discussed the possibility of changing the laws of succession to the Chrysanthemum Throne, which is currently limited to males in the male line of the Japanese imperial family. As of June 2025, there are three people ...

Public service

Prince Hitachi is the honorary president of a wide variety of charitable organizations, especially those involving international exchange. Most recently, Prince and Princess Hitachi visited

Nicaragua Nicaragua, officially the Republic of Nicaragua, is the geographically largest Sovereign state, country in Central America, comprising . With a population of 7,142,529 as of 2024, it is the third-most populous country in Central America aft ...

and

El Salvador El Salvador, officially the Republic of El Salvador, is a country in Central America. It is bordered on the northeast by Honduras, on the northwest by Guatemala, and on the south by the Pacific Ocean. El Salvador's capital and largest city is S ...

, to mark the 70th anniversary of the establishment of

diplomatic relations Diplomacy is the communication by representatives of state, intergovernmental, or non-governmental institutions intended to influence events in the international system.Ronald Peter Barston, ''Modern Diplomacy'', Pearson Education, 2006, p. ...

with both countries in October 2005. They also made a visit to France in September 2007 and

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

, marking the celebration of 110 years since the establishment of a Japanese community in this country, June 2009.

Health

Prince Hitachi suffered from fever in late February 2023 and was hospitalized on 1 March. He was diagnosed with

ureteral stones The ureters are tubes composed of smooth muscle that transport urine from the kidneys to the urinary bladder. In an adult human, the ureters typically measure 20 to 30 centimeters in length and about 3 to 4 millimeters in diameter. They are line ...

for which he underwent ureteral

stenting In medicine, a stent is a tube usually constructed of a metallic alloy or a polymer. It is inserted into the lumen (hollow space) of an anatomic vessel or duct to keep the passageway open. Stenting refers to the placement of a stent. The wor ...

the day after at the Japanese Red Cross Medical Center. He was discharged from hospital on 5 March. On 21 March, he underwent ureteral lithotripsy and was discharged on 24 March. He was readmitted to hospital with a fever and loss of appetite on 2 April, and was subsequently diagnosed with a

urinary tract infection A urinary tract infection (UTI) is an infection that affects a part of the urinary tract. Lower urinary tract infections may involve the bladder (cystitis) or urethra (urethritis) while upper urinary tract infections affect the kidney (pyel ...

. He was discharged from hospital on 24 April.

Titles and styles

* 28 November 1935 – 1 October 1964: ''His Imperial Highness'' Prince Yoshi * 1 October 1964 – present: ''His Imperial Highness'' Prince Hitachi

Honours

National honours

*: Grand Cordon of the

Order of the Chrysanthemum is Japan's highest Order (decoration), order. The Grand Cordon of the Order was established in 1876 by Emperor Meiji of Japan; the Collar of the Order was added on 4 January 1888. Unlike European counterparts, the order may be Posthumous award, ...

(28 November 1955)

Foreign honours

* : Knight of the

Order of the Elephant The Order of the Elephant () is a Denmark, Danish order of chivalry and is Denmark's highest-ranked honour. It has origins in the 15th century, but has officially existed since 1693, and since the establishment of constitutional monarchy in ...

(28 September 1965) * : Knight Grand Cross of the

Order of Merit of the Italian Republic The Order of Merit of the Italian Republic () is the most senior Italian order of merit. It was established in 1951 by the second President of Italy, President of the Italian Republic, Luigi Einaudi. The highest-ranking honour of the Republi ...

(22 November 1965) * : Member of the Order of the Benevolent Ruler (19 April 1960)

Honorary degree

* 1997: Doctor of Science,

* 2001: Doctor of Science,

* Chiang Mai University

Honorary positions

* President of the Japanese Society for the Preservation of Birds * President of the Japanese Society for Disabled Children * President of the Japan Institute of Invention and Innovation * President of the Japan-Denmark Society * President of the Dainippon Silk Foundation * President of the Japanese Society for Rehabilitation of Persons with Disabilities * President of the Japan Art Association * President of the Tokyo Zoological Park Society * President of Maison Franco-Japonaise * President of the Princess Takamatsu Cancer Research Fund * Honorary President of the Japan-Sweden Society * Honorary President of the Japan-Belgium Society * Honorary President of the Japanese Foundation for Cancer Research * Honorary President of Association Pasteur Japon * Honorary Vice-President of the

Japanese Red Cross The is the Japanese affiliate of the International Red Cross. The Imperial Family of Japan has traditionally supported the society, with the Empress as Honorary President and other imperial family members as vice presidents. Its headquarters ...

Society

Ancestry

Patrilineal descent

;Imperial House of Japan # Descent prior to Keitai is unclear to modern historians, but traditionally traced back patrilineally to

Emperor Jimmu was the legendary first emperor of Japan according to the and . His ascension is traditionally dated as 660 BC.Kelly, Charles F"Kofun Culture"Emperor Keitai (died 10 March 531) was the 26th emperor of Japan,Imperial Household Agency (''Kunaichō'') 継体天皇 (26)/ref> according to the traditional order of succession. No firm dates can be assigned to this emperor's life or reign, but he is conve ...

, ca. 450–534 #

Emperor Kinmei was the 29th emperor of Japan,Imperial Household Agency (''Kunaichō'') 欽明天皇 (29) retrieved 2013-8-22. according to the traditional order of succession. Titsingh, Isaac. (1834)pp. 34–36 Brown, Delmer. (1979) ''Gukanshō,'' pp. 261–2 ...

, 509–571 # Emperor Bidatsu, 538–585 # Prince Oshisaka, ca. 556–??? # Emperor Jomei, 593–641 #

Emperor Tenji , known first as and later as until his accession, was the 38th emperor of Japan who reigned from 668 to 671. He was the son of Emperor Jomei and Empress Kōgyoku (Empress Saimei), and his children included Empress Jitō, Empress Genmei, an ...

, 626–671 # Prince Shiki, ???–716 #

Emperor Kōnin was the 49th emperor of Japan, Emperor Kōnin, Tahara no Higashi Imperial Mausoleum, Imperial Household Agency according to the traditional order of succession. Kōnin's reign lasted from 770 to 781. Traditional narrative The personal name of ...

, 709–786 #

Emperor Kanmu , or Kammu, was the 50th emperor of Japan,Imperial Household Agency (''Kunaichō'') 桓武天皇 (50) retrieved 2013-8-22. according to the traditional order of succession. Kammu reigned from 781 to 806, and it was during his reign that the scop ...

, 737–806 #

Emperor Saga was the 52nd emperor of Japan, Emperor Saga, Saganoyamanoe Imperial Mausoleum, Imperial Household Agency according to the traditional order of succession. Saga's reign lasted from 809 to 823. Traditional narrative Saga was the second son of ...

, 786–842 # Emperor Ninmyō, 810–850 #

Emperor Kōkō was the 58th emperor of Japan,Imperial Household Agency (''Kunaichō'') 光孝天皇 (58)/ref> according to the traditional order of succession. Kōkō reigned from 884 to 887. Traditional narrative Before the emperor's ascension to the Chr ...

, 830–867 #

Emperor Uda was the 59th emperor of Japan,Imperial Household Agency (''Kunaichō'') 宇多天皇 (59)/ref> according to the traditional order of succession. Uda's reign spanned the years from 887 through 897. Traditional narrative Name and legacy Befor ...

, 867–931 #

Emperor Daigo was the 60th emperor of Japan,Imperial Household Agency (''Kunaichō'') 醍醐天皇 (60)/ref> according to the traditional order of succession. Daigo's reign spanned the years from 897 through 930. He is named after his place of burial. Gen ...

, 885–930 #

Emperor Murakami The word ''emperor'' (from , via ) can mean the male ruler of an empire. ''Empress'', the female equivalent, may indicate an emperor's wife ( empress consort), mother/grandmother ( empress dowager/ grand empress dowager), or a woman who rul ...

, 926–967 # Emperor En'yū, 959–991 # Emperor Ichijō, 980–1011 # Emperor Go-Suzaku, 1009–1045 # Emperor Go-Sanjō, 1034–1073 #

Emperor Shirakawa was the 72nd emperor of Japan,Imperial Household Agency (''Kunaichō'') 白河天皇 (72)/ref> according to the traditional order of succession. Shirakawa's reign lasted from 1073 to 1087. Genealogy Before his ascension to the Chrysanthemum T ...

, 1053–1129 #

Emperor Horikawa was the 73rd emperor of Japan,Imperial Household Agency (''Kunaichō'') 堀河天皇 (73)/ref> according to the traditional List of emperors of Japan, order of succession. Horikawa's reign spanned the years from Heian period, 1087 through 1107 ...

, 1079–1107 #

Emperor Toba was the 74th Emperor of Japan,Imperial Household Agency (''Kunaichō'') 鳥羽天皇 (74)/ref> according to the traditional order of succession. Toba's reign spanned the years from 1107 through 1123. Genealogy Before his ascension to the Ch ...

, 1103–1156 #

Emperor Go-Shirakawa was the 77th emperor of Japan, according to the traditional order of succession. His de jure reign spanned the years from 1155 through 1158, though arguably he effectively maintained imperial power for almost thirty-seven years through the ''in ...

, 1127–1192 # Emperor Takakura, 1161–1181 #

Emperor Go-Toba was the 82nd emperor of Japan, according to the traditional order of succession. His reign spanned the years from 1183 through 1198. This 12th-century sovereign was named after Emperor Toba, and ''go-'' (後), translates literally as "later"; ...

, 1180–1239 # Emperor Tsuchimikado, 1196–1231 #

Emperor Go-Saga was the 88th emperor of Japan, according to the traditional order of succession. This reign spanned the years Kamakura period, 1242 through 1246. This 13th-century monarch, sovereign was named after the 9th-century Emperor Saga and ''go-'' (後 ...

, 1220–1272 # Emperor Go-Fukakusa, 1243–1304 #

Emperor Fushimi was the 92nd emperor of Japan, according to the traditional order of succession. His reign spanned the years from 1287 through 1298. Name Before his ascension to the Chrysanthemum Throne, his personal name (his ''imina'') was . Although the ...

, 1265–1317 # Emperor Go-Fushimi, 1288–1336 # Emperor Kōgon, 1313–1364 # Emperor Sukō, 1334–1398 # Prince Yoshihito Fushimi, 1351–1416 # Prince Sadafusa Fushimi, 1372–1456 # Emperor Go-Hanazono, 1419–1471 # Emperor Go-Tsuchimikado, 1442–1500 # Emperor Go-Kashiwabara, 1464–1526 #

Emperor Go-Nara was the 105th Emperor of Japan, according to the traditional order of succession. He reigned from June 9, 1526, until his death in 1557, during the Sengoku period of the Muromachi period, Muromachi Bakufu. His personal name was Tomohito (知仁) ...

, 1495–1557 # Emperor Ōgimachi, 1517–1593 # Prince Masahito, 1552–1586 #

Emperor Go-Yōzei was the 107th Emperor of Japan, according to the traditional order of succession. Go-Yōzei's reign spanned the years 1586 through to his abdication in 1611, corresponding to the transition between the Azuchi–Momoyama period and the Edo period ...

, 1572–1617 #

Emperor Go-Mizunoo , posthumously honored as , was the 108th Emperor of Japan, according to the traditional List of Emperors of Japan, order of succession. Go-Mizunoo's reign spanned the years from 1611 through 1629, and he was the first emperor to reign entirely d ...

, 1596–1680 # Emperor Reigen, 1654–1732 #

Emperor Higashiyama , posthumously honored as , was the 113th emperor of Japan, according to the traditional order of succession.Imperial Household Agency (''Kunaichō'') 東山天皇 (113)/ref> Higashiyama's reign spanned the years from 1687 through to his abdicati ...

, 1675–1710 # Prince Naohito Kanin, 1704–1753 # Prince Sukehito Kanin, 1733–1794 # Emperor Kōkaku, 1771–1840 #

Emperor Ninkō Ayahito (16 March 1800 – 21 February 1846), posthumously honored as Emperor Ninkō, was the 120th emperor of Japan, according to the traditional order of succession.Imperial Household Agency (''Kunaichō'') 仁孝天皇 (120)/ref> Ninkō's rei ...

, 1800–1846 #

Emperor Kōmei Osahito (22 July 1831 – 30 January 1867), posthumously honored as Emperor Kōmei, was the 121st emperor of Japan, according to the List of Emperors of Japan, traditional order of succession.Imperial Household Agency (''Kunaichō'')孝明天皇 ...

, 1831–1867 #

Emperor Meiji , posthumously honored as , was the 122nd emperor of Japan according to the List of emperors of Japan, traditional order of succession, reigning from 1867 until his death in 1912. His reign is associated with the Meiji Restoration of 1868, which ...

, 1852–1912 #

Emperor Taishō , posthumously honored as , was the 123rd emperor of Japan according to the traditional order of succession, reigning from 1912 until his death in 1926. His reign, known as the Taishō era, was characterized by a liberal and democratic shift in ...

, 1879–1926 # Emperor Shōwa, 1901–1989 # Masahito, Prince Hitachi

References

External links

Their Imperial Highnesses Prince and Princess Hitachi
at the Imperial Household Agency website {{DEFAULTSORT:Hitachi, Prince 1935 births Living people People from Chiyoda, Tokyo Gakushuin University alumni Sons of Japanese emperors 20th-century Japanese scientists 21st-century Japanese scientists Cancer researchers Tokyo University of Science alumni Children of Hirohito