An information processing system includes an image search system and a customer-side system. The image search system includes a module distributer and a searcher. The module distributer is configured to distribute a search module and module identification information to the customer-side system while associating the search module and module identification information with each other. The search module is used for causing a terminal device to transmit the search request; the module identification information is used for identifying the search module. The searcher is configured to, as a result of causing the search module to run on the terminal device, execute the searching of the databases in accordance with the module identification information. The module distributer distributes, to the customer-side system, the search modules associated with different pieces of module identification information.