Morikawa et al. (1998) designed HyperMirror which is a new video image communication tool. Unlike the traditional video conferencing system, HyperMirror uses composited video image with chromakey effect (Figure 1). For this, HyperMirror allows local and remote participants to feel as if they are in the same room, share materials, and do collaborative activities (eg. Figure 2). In addition, partici- pants can interact naturally because their own image is reversed and appears just as if they were looking in a mirror.