At Tokyo's Sign & Display Show 2008, Teraokaseiko presented a curious concept: a two-way touchscreen display. And showed how it can be used to play tic-tac-toe and sea battle. The 256 × 120 monochrome display is a transparent inorganic electroluminescent panel. The trick is that Teraokaseiko engineers placed resistive sensor films on both sides of the display. The result was a device that recognizes not only touch, but also movement. According to the developers, their concept, if it ever becomes a commercial product, will be useful in devices for working with mapping software and for games with two users.