A counterpart terminal information management system (50) includes: a terminal manager (5002) that manages, for each one of a plurality of terminals (10), terminal identification information for identifying the terminal, and terminal related information previously set by default, in association with each other; a counterpart terminal manager (5003) that manages, for each one of the plurality of terminals (10), the terminal identification information for identifying the terminal, counterpart terminal identification information for identifying a candidate counterpart terminal that may be requested by the terminal to have communication with, and counterpart terminal related information individually set by a user who operates the terminal (10), in association with one another; a receiver (51) that receives, from a first terminal (10aa), a request to share a candidate counterpart terminal managed for the first terminal (10aa) with the second terminal (10ac), and information indicating whether to permit or reject sharing of the counterpart terminal related information individually set by the user of the first terminal (10aa) with the second terminal (10ac); and a transmitter (51) that transmits information regarding the candidate counterpart terminal managed for the first terminal (10aa) to the second terminal (10ac). In response to the information indicating to permit sharing of the counterpart terminal related information, the transmitter (51) transmits the counterpart terminal related information of the candidate counterpart terminal to be shared, which is managed by the counterpart terminal manager (5003) in association with the terminal identification information of the first terminal (10aa). in response to the information indicating to reject sharing of the counterpart terminal related information, the transmitter (51) transmits the terminal related information of the candidate counterpart terminal to be shared, which is managed by the terminal manager (5001) in association with the terminal identification information of the candidate counterpart terminal.