Michiko Nagai (永井路子 Nagai Michiko?); (born March 31, 1925) is a writer of historical fiction in Japan.
Born in Tokyo, Nagai graduated from the Tokyo Women's University with a degree in Japanese literature in 1944. She also studied economy history at the University of Tokyo from 1947-1948. After her marriage to the Nobuo Kuroita, the son of historian Kuroita Katsumi, she went to work for the Shogakukan Publishing Company as an editor, but began to write her own stories with historical settings on the side.
In 1952, she submitted her debut work, Sanjoin ki ("History of Lady Sanjo") to the Sunday Mainichi, where it was awarded second place in the 30th anniversary commemorative edition of that publication. This encouraged her to pursue a career in literature full-time, winning the prestigious Naoki Award in 1964, the 21st Women's Culture Award in 1981, the 32nd Kikuchi Award in 1984 and the Yoshikawa Eiji Literary Award in 1987.
She is noted for historical novels reassessing the role of women in Japanese history. She is praised for combining historical accuracy with translating her characters emotions into modern terms. In Masako, she countered popular image of Minamoto no Yoritomo's jealous, power-grasping wife Hojo Masako (1157–1225) with a more human, sympathetic personality. Her novel was the basis for a yearlong television drama on the Japanese government television network NHK, in 1979.