After the Second World War, an obedience-dominance relationship between Japan and the U.S. took shape during the occupation era, which became the prototype of postwar U.S.-Japan relations. Ever since the 1960s, the U.S. and Japan have both sought to develop a more comprehensive and balanced partnership, but the obedience-dominance pattern has still prevailed. “Power,”which was often emphasized by realist international relations theories, was not the only impetus for the relationship. From the perspective of Psychoculturalogy, the human constant difference between Japan and the U.S. was the key to the formation of the obedience relationship of the“oyako pattern.”