Haruko Koshihara was born in Higashi-Shirakawa Village, Kamo County, Gifu Prefecture in 1885. She aspired to become a teacher from early on. Competing with adult applicants, she passed the examination for Gifu Prefectural Teachers' Training School in Iwamura. Upon graduation, she started to teach at an elementary school in her native village at the age of 15. She founded Nagoya Girls' School with Yamato Koshihara in 1915, and devoted herself to the management of the school and women's education for more than 40 years. In 1946, women acquired the right to vote in Japan, and Haruko became one of the first female members of the House of Representatives in the Diet. As a member of the Constitution Council, she strove to liberate women and improve their position in society―a cause she had long advocated.