Studies have been conducted to examine the human body perception of a whole body when having multiple bodies. In this paper, we investigate how does the sense of body ownership and the sense of agency change when a user synchronously moves multiple body parts in a virtual environment. Participants in a demonstration will perform a reaching task for 150 seconds by physically moving their right hands while visualised as one or nine hands in a virtual reality environment. At the end of the reaching task, a threat stimulus is triggered and participants' electromyography are measured as an objective index of the sense of body ownership. Finally, a short survey will be conducted to query the strength of the subjective sense of body ownership and agency.