Approximately 40% of the population enjoy access to the Internet via mobile phones in Japan, where user needs have driven developments of the mobile Internet such as "i-mode". After reviewing mobile Internet services in Japan, this article examines key social and cultural factors of mobile Internet use based on nationally representative surveys focusing on differences between PC and mobile Internet. The results demonstrate that mobile Internet is a more time-enhancing activity while PC Internet is a more time-displacing activity. Additionally, this article discusses unique Japanese cultural factors affecting communication patterns characterized by the high disclosure of subjective self and low disclosure of objective self, which may explain the unique usage patterns of the mobile Internet in Japan.
