Communication systems, communication terminals and communication methods are provided. A communication system has a infrared communication capability and a wireless data communication capability including, a first terminal for storing provisional setting information for wireless data communication containing identification information of the first terminal, and a second terminal having the infrared communication capability and the wireless data communication, wherein the provisional setting information is transmitted from the first terminal to the second terminal by the infrared communication capability, the second terminal generates first setting information with the first terminal specified as a destination of connection on the basis of the received provisional setting information, the second terminal makes wireless data communication with the first terminal on the basis of the first setting information and, if the wireless data communication is successful, transmits a connection completion notice to the first terminal, and the first terminal, having received the connection completion notice, updates the provisional setting information to generate second setting information with the second terminal specified as a destination of connection, thereby establishing wireless data communication between the first terminal and the second terminal.