We propose an alternative approach to find each robot's unique communication strategies. In this approach, the human manipulator behaves as if she/he becomes the robot and finds the optimal communication strategies using attachable and detachable robot's shapes and modalities. We implement the system including a reconfigurable body robot, an easier manipulation system, and a recording system to evaluate the validity of our method. We evaluate a block-assembling task by the system by turning on and off the modality of the robot's head. Subsequently, the robot's motion during player's motion significantly increases whereas the ratio of confirmatory behavior significantly decreases in the head-fixed design. In this case, the robot leads the users and the user follows the robot as in the turn-taking communication style of the Head-free condition.