She was the granddaughter of Prince Masayoshi Matsukata, on her father's side, and businessman Ryoichiro Arai was her maternal grandfather.

[1] Her mother was born in New York City, and was one of the first Japanese adherents to Christian Science.

[2] Matsukata graduated from Principia College in Illinois in 1941,[3][4] and earned a master's degree in library science from Columbia University.

[9] Eleanor Roosevelt mentioned Matsukata and her sister Haru in a 1953 My Day column, saying "They are running a small school where children of eight nations come to learn English.

"[10] The Tokyo mansion her parents commissioned by American architect Merrell Vories Hitotsuyanagi in the 1920s became one of the school's buildings.