This paper reports on the development of a multirobot cooperation system for human-robot communication in which robots behave as if communicating by speech, while the system exchanges information through a network that maintains natural communication timing. The information exchanged through the network is based on the analysis of interhuman conversation. This system is based on a scripting language for coordinating multirobot communication, which has a merit for developers: easy development. The developed system is used for Manzai, which is a kind of a Japanese stand-up comedy mainly performed by two persons. While tempo and timing are particularly important in Manzai, the developed "robot Manzai" system received higher evaluations than the Manzai shown in a video performed by humans. We believe that this system demonstrates the potential of robots as a passive-social medium, including television and computers. © 2008 World Scientific Publishing Company.