An information processing system is connected to a first external device via a network. The information processing system includes circuitry configured to perform: obtaining voice information for operating the first external device; recognizing the voice information obtained at the obtaining; interpreting, from a recognition result obtained at the recognising, processing information indicating processing to be performed in the first external device, first address information identifying the first external device, and second address information identifying a second external device to which the first external device is to send a result of the processing; and sending instruction information including the processing information and the second address information, to the first external device identified by the first address information.