A three-dimensional object for which three orthogonal object axes are set is disposed in a virtual space. One or two of the three object axes are determined as an enlargement/reduction axis, based on an orientation of the three-dimensional object in the virtual space. A user's operation input is associated with the enlargement/reduction axes. The three-dimensional object is at least enlarged or reduced based on the association of the user's operation input with the enlargement/reduction axes.