Minami was born 1911 in Toyama and graduated from Takaoka Women’s School in 1928. While she was already interested into poetry and painting around this time, in was only in 1945 when Minami moved to Tokyo, that she became acquainted with the novelist Ineko Sata and started to write her own children’s stories. From 1949 to 1958, Minami exhibited regularly at the Free Arts Exhibition. She met her future husband Yozo Hamaguchi at the atelier of Yoshio Mori where she was taking classes in oil painting.

In 1954, Minami moved to France and enrolled at the studio of Johnny Friedlander. The Kanagawa Prefectural Museum of Modern Art in 1961 held the exhibition “Johnny Friedlander, Yozo Hamaguchi and Keiko Minami.” Minami moved to San Francisco in 1982, and returned to Japan in 1996. While continuing to exhibit internationally, Minami also worked as an illustrator. She died in 2004.