This chapter focuses on hate speech in Japan from the perspective of social psychology and adjacent fields. First, the author discusses the definitions of and the debate around the social psychological concepts of stereotypes, prejudice, and discrimination, and how these concepts are interrelated. The importance of constructing social norms against hate speech and suppressing opportunities to deliver hate speech are discussed. Second, he discusses a series of applied research conducted mainly in Japan. Quantitative analyses of posts on social media reveal the characteristics of hate speech in Japan, as well as underling beliefs and attitudes. Specifically, themes such as ‘modern or symbolic racism’, ‘old-fashioned racism’, ‘historical revisionism’, and so on, were evident in these posts. Furthermore, these and other studies show that relatively few people are disproportionately able to bias the discourse on politically controversial topics. Questionnaire surveys show a consistent association between Internet usage and negative attitudes towards people from outside Japan. Together, these quantitative studies show how detrimental the information age can be in the absence of sufficient regulations.