She worked as a medical doctor in the Department of Psychiatry at Tokyo University following World War II.
She was said to have greatly helped the Ministry of Education and the General Headquarters, where the Supreme Commander of the Allied Powers stayed, in her role as an English-speaking secretary, and served as an adviser to Empress Michiko.
Tamon, a son of an Osaka merchant, was the prewar Japanese ambassador to the International Labour Organization and postwar Minister of Education.
In 1921 he was appointed the Japanese representative to the International Labour Organization (ILO) at Geneva, Switzerland, where Inazo Nitobe worked as one of the Under-Secretaries General of the League of Nations.
She contracted tuberculosis, and while she was under treatment for the disease, she studied by herself classical literature in many languages, including Italian, French, German, and Greek.
In 1938, in view of the worsening US-Japan relations, Japan set up a Japan Culture Center in New York, and her father, who was one of the editorial writers of the Newspaper Asahi Shimbun, was appointed as its head and the family moved to New York, except her elder brother, Yoichi Maeda, who lived in Paris.
Kamiya began to study Greek literature at the Graduate School of Columbia University and lived with her family in Scarsdale, New York.
After her health condition improved, Kamiya studied at Bryn Mawr College from February to the end of June 1939.
She met Masa Uraguchi, who was a graduate student of botany at Philadelphia University and who became her lifetime best friend.
She also met Wilhelm Sollmann, who was a German journalist, politician, and Interior Minister of the Weimar Republic.
After Japan's defeat in World War II, her father was appointed Minister of Education, and Kamiya was asked to become a secretary.
In May, she returned to Tokyo University and helped to examine Shūmei Ōkawa who was a prisoner of the International Military Tribunal for the Far East.
Kamiya stated that those who have firm ikigai would be those who realize their own mission, or purpose in life, and who are deliberately progressing toward their goals.
They are usually not distinguished persons; they may be teachers at secondary schools, or those engaged in special education, or those working in hospitals in remote areas.
Paul Gauguin may be cited as someone who experienced this, as he started his career as a stockbroker, but went into drawing art at the age of 35.
According to Kamiya, the fundamental role of religion is to give a person unified standards of value, or ikigai (meaning of life).