In this paper, we develop a novel participatory simulation platform, called gumonji/Q, by integrating scenario description language Q and network game gumonji. In a participatory simulation, humans and software-agents coexist in a shared virtual space and jointly perform simulations. To observe practical behaviors of humans, a participatory simulation platform must be able to provide reasonable simulated experience for humans to let them behave as they do in the real-world. gumonji/Q makes it possible to design diverse interaction protocols based on Q's scenario description ability. Under the "game-quality" graphics provided by gumonji, humans and agents can interact with their surrounding environment, which means they can affect the environment and receive feedback from the environment. Since gumonji/Q inherits gumonji's features as a network game, users are more enticed to participate in simulations since simulations on gumonji/Q seems more enjoyable than normal simulations. We show an example of how to obtain human behavior models through a simulation on gumonji/Q.