This system 1 accepts content marker information including content identifier information for identifying content, and executes a process of causing a storing device to store the accepted content marker information. The system 1 accepts sharing-user identifier information for identifying a user/users who shares/share the stored content marker information. The system 1: accepts a content marker output request that includes user identifier information for identifying a user and that is a request for an output of content marker information; based on the user identifier information included in the accepted content marker output request and the accepted sharing-user identifier information, extracts content marker information corresponding to the user identifier information from the stored content marker information; and outputs the extracted content marker information.