According to the report submitted by the Evaluation Committee of Experts, Government ICT Strategy Headquarters in December 2005 (ECE, 2005), Japan has already established the globally advanced e-government infrastructures for such services as online application and filing. The report also acknowledged that the quantity and quality of information, guidance and search engine at the government portal, “e-Gov”, and individual government Web sites have reached almost the same level as those of the government Web sites of the other world-famous ICT nations. These achievements have resulted from the continuous undertaking of introducing information and communication technologies (ICTs) in the government operations from 1960s (ECHMCA, 2001). In this article, the successful accomplishments of e-government initiative are described followed by the analysis of institutional arrangements and mechanisms concerning e-government initiatives. Lastly, the future challenges will be suggested.