An information-processing apparatus including a reproducer for synchronously reproducing content data common to another information-processing apparatus, a user information input for inputting first user condition information including a voice and image of a user, a user information receiver for receiving second user condition information including a voice and image of an other user from the other information-processing apparatus, a synthesizer for synthesizing a voice and image of the content data synchronously reproduced by the reproducer with the voice and image of the second user condition information received by the user-information receiver; an information analysis unit for analyzing at least either the first user condition information input or the second user condition information; and a parameter-setting unit for setting a control parameter used for controlling a process on the basis of an analysis result produced by the information analysis unit.