We proposed an approach for effectively supporting the learning of basic geometry. We designed and implemented an electronic paper craft modeling system to achieve the goal. The proposed system allows users to intuitively observe and manipulate 3D geometric models in a virtual 3D space. The users can improve their knowledge and skills on geometrical techniques by iteratively performing various 3D operations supported by the system. We also prepared a touch-based interaction environment for evaluating the system from viewpoints of the easiness, efficiency, and usefulness for using the system. Although the evaluation still is a preliminary stage, we found the result is a promising one. Conducting more precise experiment to quantitatively evaluate the system is an urgent issue in the near future.