On a participation member screen image of a chat room, user information is displayed such that a host user and a guest user who perform share play can be specified. In a member information area, an information displaying field for the host user and an information displaying field for the guest user are disposed in a juxtaposed relationship from the uppermost stage, and a share play mark is added to the host user. Further, in a share play item, a check mark is displayed to indicate that share play is proceeding, and time information is displayed to indicate an implementation time period of the share play.