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 chroma-key effect (Figure1). For this, HyperMirror allows local and remote participants to feel as if they are in the same room, share materials, and do callaborative activities (eg. Figure2). In addition, participants can interact naturally because their own image is reversed and appears just as if they were looking in a mirror.