Paper-folding is an educational activity to enhance a creativity of children because a paper-folding game is to create various 2D or 3D shapes by folding a plane square paper with both hands. However, since previous paper-folding games provide folding designs as books, children may need a guidance of a teacher or may degrade interest. In addition, existing computer-based games have simple interfaces with one or two fingers and thus they are difficult to have direct influence on children's physical development and creativity enhancement. In this paper, we propose a computer-based paper-folding game which children fold a real paper with two hands and a computer with a camera gives various feedback. The proposed game is developed based on the CAI concept and contains elements of the Keller's ARCS theory.