A system configured to control a mobile body to move in accordance with movement of a person is provided. The system acquires information indicating a position and a moving direction of a person. The system acquires a graph that includes nodes and edges and indicates a movement route of the person. The system determines a first edge of the graph corresponding to the position of the person based on the position of the person. The system decides a movement target position of the mobile body based on the first edge or on one or more edges located in the moving direction of the person with respect to the first edge.