An exchange is provided with a data synthesizer that synthesizes moving picture data that are being communicated between terminals with additional moving picture data, and is capable of inserting the additional moving picture data into the moving picture data that are being communicated. Each terminal is provided with a data transmission/reception means that both synthesizes the moving picture data that are being transmitted to the terminal of a communication partner with the additional moving picture data and synthesizes moving picture data that have been transmitted in from the terminal of a communication partner with additional moving picture data; and is capable of inserting additional moving picture data into the moving picture data when the moving picture data are being transmitted or received. In a case in which additional moving picture data are inserted into moving picture data that are being communicated between terminals, the additional moving picture data are inserted into the moving picture data that are being communicated at either the terminals or the exchange.