An information-processing apparatus includes: a link information-generating portion that reads two or more pieces of operation information having a user identifier and an object identifier for identifying an object on which a user has performed an operation, detects two or more object identifiers linked via a user identifier contained in the two or more pieces of operation information, and generates link information indicating a link relationship between two or more objects; an object identifier-accepting portion that accepts one object identifier; an in-group object identifier-acquiring portion that acquires an object identifier having at least a predetermined level of relevance with the one object identifier accepted by the object identifier-accepting portion, using the generated link information; and an in-group object information output portion that outputs object information, which is information related to an object identified with the object identifier acquired by the in-group object identifier-acquiring portion.