Nagako, Empress and later Empress Dowager of Japan, consort to the Emperor Showa Hirohito, (March 6, 1903 - June 16, 2000) and mother of the Emperor Akihito.

The Empress Nagako, known posthumously as Empress Kojun, was the longest lived empress consort (kogo) in Japanese history. She was Crown Princess from 26 Jan. 1924 to 25 Dec. 1926, Empress from 26 Dec. 1925 to 7 Jan. 1989, and Empress Dowager from 7 Jan. 1989 to 16 Jun. 2000. Princess Nagako (Nagako Nyoō), was born on 6 March 1903 in Tokyo, the eldest daughter of Prince Kuni Kuniyoshi (Kuni no miya Kuniyoshi ō, b. at Kyoto 23 Jul. 1873, d. at Atami 29 Jan. 1929), by his wife, Chikako (b. at Kagoshima 19 Oct. 1879, d. at Tokyo 10 Sept. 1956), the 7th daugther of Prince Shimazu Tadayoshi [peer], former lord of Satsuma, 29th and last daimyo of the line. Prince Kuni Kuniyoshi, a son of Prince Kuni Asahiko, was the head of one eleven cadet branches of the imperial family during the Meiji and Taisho periods. Princess Nagako attend the Girls' Department of then-Peers' School (now Gakuishun).

The January 1919 engagement of Princess Nagako to her distant cousin then-Crown Prince Hirohito was unusual in two respects. First, she was a princess of the imperial blood (albeit a minor one), whereas for centuries the chief consorts of Japanese emperors and crown princes had come one of the five senior branches of the Fujiwara clan (Konoe, Ichijô, Nijô, Takatsukasa, and Kujô), the most illustrious families of the court nobility or kuge. Second, although Princess Nagako's father was an offshot of the imperial family, her mother descended from daimyo, the feudal or military aristocracy.

Princess Nagako married then Crown Prince Hirohito on 26 January 1924 and became empress upon his accession to the throne on 25 December 1925. The Emperor and Empress had seven children, five daughters and two sons: Princess Teru (Shigeko), b. 9 Dec. 1925, d. 23 July 1961), later Mrs. Higashikuni Morihiro; Princess Hisa (Sichiko), b. 10 September 1927, d. 8 March 1928; Princess Taka (Kazuko), b. 30 September 1929, d. 28 May 1969, later Mrs. Takatasukasa Toshimichi; Princess Yori (Atsuko), b. 7 March 1931, now Mrs. Ikeda Takamasa; the present Emperor of Japan, Akihito, b. 23 December 1933; Prince Yoshi (Masahito), b. 28 November 1935, titled Prince Hitachi (Hitachi no miya) since 1 October 1964; and Princess Suga (Takako), b. 3 March 1939, now Mrs. Shimazu Hisanaga. The daughters who lived to adulthood, left the imperial family as a result of the American reforms of the Japanese imperial household in October 1947 (in the case of Princess Higashikuni) or under the terms of the 1947 Imperial Household Law (in the cases of Princesses Yori, Taka, and Suga).

Although she performed her ceromonial duties as empress in a traditional way, the Empress was the first Japanese imperial consort to travel abroad. She accompanied Emperor Showa on his European tour in 1971 and later on his state visit to the United States in 1975.

After the Emperor Hirohito's death in 1989, she assumed the title of Empress Dowager. At that time she was in failing health herself. Her last public appearance was in 1988. At the time of her death at the age of 97 in 2000 she had been an empress for 75 years. Emperor Akihito granted his mother the posthumous title of Empress Kojun.