This cube is designed by Oskar Deventer, the Dutch Puzzle inventor. The position of the piece trapped inside can be changed by it being moved in a unique way. However, the dilemma is… how do you remove that piece? When it was first invented, the start point at which the piece can be removed was not fixed. However, following a suggestion by the late Mr. Nob Yoshigahara, the furthermost position was made to resemble a face, and a clear removal start point was thereby designated. The theme is “space.