An information processing device includes a content database storing contents with metadata and a keyword associated with each content, the metadata which accompanies each content and includes a plurality of items of data, a user database storing user identifiers with a specific item of the metadata associated with each user identifier, an acquiring unit acquiring new content and new metadata, an identifier extracting unit extracting a user identifier from the new metadata, a specific item specifying unit specifying a specific item associated with the extracted user identifier based on the user database, a keyword extracting unit extracting from the content database keywords associated with data identical to data of the specific item in the new metadata, a keyword selecting unit selecting a keyword from the extracted keywords, and a registration unit registering in the content database the selected keyword in association with the new content and the new metadata.