The Yomiuri and Mainichi newspaper chains inaugurate the Nichi-Bei Series, a program of regular visits by American major-league clubs to Japan. The program will be sponsored by the Yomiuri chain alone from 1966.

This Day In Baseball

On July 12, 1953The Yomiuri and Mainichi newspaper chains inaugurate the Nichi-Bei Series, a program of regular visits by American major-league clubs to Japan. The program will be sponsored by the Yomiuri chain alone from 1966.

Source
Baseball Reference July 12