Abstract: Every culture has its own interpersonal rules, explicit or latent. Explicit rules emphasize rationality and formal rules, but unspoken rules emphasize emotions, relationships and informal rules. As a kind of interpersonal rules, unspoken rules are also in essence rules of exchange. Social exchange behavior occurs not only between individuals, but also between various groups representing individuals. Countries are relatively large groups of humans. In fact, the socalled diplomatic behavior between countries is a human exchange behavior. The unspoken rules of interpersonal behavior will naturally affect the communication between groups and even between countries. For an anarchic international society, the influence of unspoken rules of culture on diplomatic behavior in different countries cannot be ignored. Japanese governments attitude towards “the Kono Statement” typically reflects the influence of Japanese unspoken rules of culture on its diplomatic decisions.

Key words: Japanese national character, unspoken rules of culture, psychoculturology, diplomatic decisions, the Kono Statement