To enhance practicality for an information processing system with an information processing device, such as a PC, a game console for household use and the like in the system, by making their behavior associated with the meaning as well as playful touches.

With the main part of system 100 with a display part for displaying a message and a pseudo-living creature device 200, which is connected to the main part of the system though wired or wireless and behaves, according to behavioral data, the message is allowed to include the behavioral data representing the behavior of the pseudo-living creature device, the main part of the system is constituted with a behavioral data extracting part for extracting the behavioral data from the message and a behavior control part to transmit to the artificial living creature device the behavioral data extracted, by the behavioral data extraction part or the behavioral data generated, based on the behavioral data extracted.