The present invention is related to an information processing system that simultaneously shares content data in private virtual spaces. A home server is arranged at a user's home. A portable user terminal can access the home server and a virtual home DB server supplies the layout information about virtual home to the portable user terminal. An authentication server executes authentication processing on the portable user terminal. An inter-user-terminal communication relay server executes the processing associated with the communication between a plurality of users. A user information holding server stores the personal data of each user and the content data, which are shared with other users. This system thus realizes realtime communication via the Internet.