This box was made as a Christmas present for Karakuri Club members in 2005. Kamei divided a cube into four trigonal pyramids. Of course Kamei had tocreate a new way of opening it and the new mechanisms for this box only. Atfirst Kamei imagined that each trigonal pyramid should move radially. ButKamei gave up this design because the mechanism became too complicated.Finally Kamei decided on Translation.