The term of “social media” appears in newspapers and magazines everyday and the huge number of people use social media actively in daily life. Nowadays, in the highly Information and Communication Technology (ICT) developed country Japan, Japanese people enroll in social media and evolve a new way of communicating with others based on the “virtual” social distance between them. Among social media, Twitter has been focusing on its strong power as the tool for political change recent years. While Twitter has of-expressed problems as well as the “traditional” social media, it is characterized by the limited number of characters, strong propagation and optional reciprocity. Those characteristics stimulate people’s communication online and bring about opportunities for social interaction and democratic dialogue. On the other hand, in the deluge of information, we need to nurture skills to utilize critical and rational way of thinking through dialogue not only between others also between themselves internally. This study explores characteristics of social media and differences between “traditional” social media and Twitter, and how the difference affects people’s information behavior in Japan.