 In 1959, Itaru was sent to Prague, Czechoslovakia as an editor of "The Problems on Peace and Socialism", an international communist party magazine and his family accompanied him.Mari initially studied the Czech language, but her father placed her in an international school run by the Soviet Union, where education was conducted in Russian language so that his children were able to continue the language in Japan.The school curriculum was heavy on communist indoctrination, and Yonehara's classmates included children from over 50 countries.