An object of the present invention is to provide a novel information management program or system for mutually distributing and managing information limited by an information provider in terms of target for disclosure, for example, personal contact information such as contact information and private messages. A storage medium of a center system stores therein personal self-information, a receivers list, and a senders list as user information and personal contact information on other person as a sender's personal contact information database for each user, and the information processing device, when personal self-information stored in the storage medium is input or changed by a user, checks whether or not the user is registered for a sender on a senders list on each receiver, for each receiver registered in a receivers list on the user, and only for the registered receiver, writes at least some of the input or changed personal self-information in a sender's personal contact information database on the receiver stored in the storage medium, thereby automatically updating the content of the senders' personal contact information database on the receiver.