Provided is a system that includes circuitry that transmits first image data to a second communication terminal in response to a first request for image transmission from a first communication terminal; transmits second image data to the first communication terminal in response to a second request for image transmission from the second communication terminal; and transmits, in a case that the first request for image transmission and the second request for image transmission are a predetermined combination, third image data corresponding to the predetermined combination to the first communication terminal and the second communication terminal.