She was educated at the school her parents founded, Jiyu Gakuen.
[1][2] Hani was a reporter and teacher as a young woman.
She was one of the founders of the Women's Democratic Club (Fujin minshū kurabu) in March 1946,[3] and joined Shidzue Kato, Yoko Matsuoka (who was also Hani's cousin), and other feminists in presenting a statement to General Douglas Macarthur on women's rights in post-war Japan.
[4] As a "child welfare expert", she expressed concern for the children born to Western fathers and Japanese women during the post-war occupation.
[5] In 1955 she was one of Japan's five representatives at the Women's International Democratic Federation (WIDF) meeting in Geneva.