The objective of this dissertation is to explore the socio-cultural contextualization of the digital divide in Japanese society. I undertake this task by developing a theoretical and methodological framework based on the notion of "culture as models," while explicating the cultural dimensions of the digital divide and the dynamics of ICTs, information and communication technologies, in society. It has become evident that "the digital divide" is not a matter of access to the PC-based Internet, but of different access means with a wide range of speeds and a great variety of use, as well as a matter of ICT skills, literacy and social support. The commercialization and social diffusion of advanced ICTs, such as FTTH, Fiber to the Home, and 3G mobile network, has been astounding in Japan, compared with other industrialized societies, while social diffusion of the Internet and mobile phones at large has been rather limited and a considerable number of Japanese fall through the network. Given the context, this thesis presents a comprehensive picture of the development of the digital divide or social diffusion of different kinds of ICTs in Japanese society. Examining the "Falling through the Net" in Japan reveals that the world's most advanced and cutting-edge ICT equipment and services have been developed and commercialized aggressively in this country. However, due to a huge amount of investment in R&D and commercial deployment of such services, prices and charges for ICT services tend to be rather high. Thus, a considerable number of people fall through the network. Close scrutiny of documentation related to ICT policy of the Japanese government reveals that the government has relied on several significant "cultural models" that help to justify its prioritizing of the development of an advanced ICT infrastructure, especially concerning the establishment of a trunk network of fiber optics, while neglecting the need to stimulate the social use of ICT applications and human resource development. The issue of the digital divide and its surrounding policy measures are also formulated based on the same cultural models as general ICT policy. Policy measures for coping with the digital divide have been composed of two different kinds of initiatives. The one is concerned with nationwide infrastructure development "to correct the telecommunications gap"; the other is "the initiative to facilitate ICT use among the elderly and the disabled."As far as the social distribution of wealth, opportunity and risk is concerned, the Japanese government subscribes more to a residual approach than to a universal approach. On the other hand, it would seem that the Japanese government holds a universal approach regarding infrastructure development. An examination of cultural models on the part of business and citizens/users indicates that the Japanese consider advanced ICTs as common commodity goods for enjoyment and information seeking. In addition, business has tried to bind customers to exclusive use of its service and to gain as much ARPU (average revenue per user) as possible, so as to develop and introduce new products and services aggressively. Therefore, while many Japanese can enjoy advanced ICTs, as many are left behind and Japan lags in terms of the social diffusion of the Internet and the social use of information networks. When it comes to the digital divide in ICT use among the Japanese, compared with the Koreans, the Finns, and the Americans, two different kinds of "use divide" are distinguished in Japanese Internet use. One of these is the phenomenon that even though advanced features of ICTs are commercialized and available for use in Japan, the actual usage of various features and functions is very low. The other type of use divide refers to the fact that even among the Japanese citizens who practice online communications to some extent, the dynamics between social interaction in cyberspace and that in the offline lived-in world are inclined to be lacking and they are divided from each other despite the wide availability of advanced technologies. After describing this phenomenon, I explicate the digital divide in use as a "communicative ecology" in Japanese society, and probe for the cultural models that serve as its underlying generative forces. I go on to explore cultural models that have to do with this communicative ecology: (1) "kuuki wo yomu" (to read the atmosphere), (2) the distinction between the cultural model of "shinrai" trust and that of "anshin" assurance, and (3) "kan-media-sei," the strong co-dependency between the mass media and the Internet. Based on the exploration of these cultural models, I postulate a framework or a model of integrated communicative ecology to interpret the relationship between the activities in cyberspace, the mass media, and the offline world. (Abstract shortened by UMI.) [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. 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