A request possibility determination unit 13 for a communications terminal 1-1 determines whether or not communications time required for obtaining data from a communications terminal 1-2 can be secured, between the communications terminal 1-2 and the communications terminal 1-1. A data acquisition unit 12: determines data that has not been stored in a data storage unit 14, among data on a list received as a result of a communications message from another communications terminal 1-2; and requests the determined data from the communications terminal 1-2, by using a communications message on the condition that the request possibility determination unit 13 has determined that communications time can be secured.