1. A simulator system comprising: a first simulator simulating a behavior, including movement in a virtual space, of a plurality of simulation targets of a first kind, a second simulator simulating a behavior, including movement in the virtual space, of a simulation target of a second kind, wherein the first kind of simulation targets are different from the second kind of simulation target, and an intercommunication control device connected via a network to each of the simulators, wherein: each of said simulators comprises a selective notification device to select one or more of the predetermined simulation targets located in a predetermined region of the virtual space that satisfy a predetermined notification condition and to send information related to the one or more selected simulation targets, excluding others of the predetermined simulation targets not located in the predetermined region of the virtual space, to the intercommunication control device via the network, said predetermined notification condition including a possibility of carrying out one or more mutual actions with another of the predetermined simulation targets simulated by another of said simulators, the intercommunication control device comprises: a holding device for holding processing designation information to designate a processing content to be executed when information related to the simulating targets is received from the simulators via the network identified by the information in relation to information identifying at least one simulator, said processing content including one or more judgment conditions showing whether or not there are mutual actions between two or more of the simulation targets related to which information is received from the corresponding simulators via the network, and a mutual processing execution device for executing processing of the content predetermined by the processing designation information on the basis of the information related to the simulation targets received from each of the simulators via the network, the processing including judging whether or not there are mutual actions between the simulation targets related to which information is received from the corresponding simulators, and notifying the result of the processing to the simulators via the network.