The purpose of this chapter is to review how the principles of organization and group formation operating in contemporary Japan serve to maintain a social structure which is compatible with long-standing emphasis upon the values of loyalty and harmony. This structure facilitates the consensus-building approach to Japanese decision-making, whose patterns will be examined to show that the process, like on-giri, is a convention which channels the expression of amae. Groupism results in factionalism, whose persistent appearance in Japanese politics despite dysfunctional aspects suggests that the needs of amae form the most potent incentive for factionalism, and many other institutionalized patterns of social and political behavior.