This master's thesis is a grounded theory study of the development of the Internet as a tool for political action in Japan by groups and individuals producing web pages on the issue of history textbook reform. Through the analysis of 14 in-depth interviews, a framework is developed for understanding the role the Internet has taken in political action in Japan. As activists utilize the Internet in political activism, the Internet appears to be developing into an anchor for continuing political activism. For activists, the Internet is a central point of reference for both mass communication and interpersonal communication activities. The model indicates that the political alignment of an activist is an important factor in determining his or her preference for either interpersonal or mass communication on the Internet. Activists on the left tend to use the Internet as a tool for interpersonal communication and coordination, while activists on the right tend to view the Internet as a tool for mass persuasion. The model of Internet activism developed in the thesis is also compared with models of communication derived from theories of technological determinism and social shaping of technologies. Consistent with technological determinist ideas, the Japanese case demonstrates that as activists rely on the Internet, other media show signs of becoming content for the new medium. However, the Japanese case also shows that pre-existing needs and the political framework of an activist have a strong shaping effect on Internet use, indicating the importance of a social shaping of technologies approach.