Abstract. Network games are attracting attention as simulation platforms for social experiments because of their rich visualization performance and scalability. Our objective in this study is to develop a participatory simulation platform on a network game. Unlike non player characters (NPCs) in network games, agents in a participatory multiagent-based simulation (PMAS) should behave as real-world humans according to behavior models. We developed a novel networked participatory simulation platform called gumonji/Q by integrating scenario description language Q with the network game gumonji. This paper details the implementation of gumonji/Q. In order to connect Q and gumonji, we implement communication sub-components that realize TCP/IP communication between them, and a scenario translator to convert a request from Q into a sequence of operators. This makes it possible for the gumonji simulator to deal with human-controlled avatars and Q-controlled agents in a unified way.