1. A computer-readable storage medium readable by a processor of a touch input device having a first display and a second display arranged on respective left and right sides with respect to a predetermined axis and a touch panel provided on the second display, the recording medium holds a touch input program, the touch input program causes the processor to execute: setting a reverse input mode in response to a predetermined operation; accepting through the touch panel a handwriting input operation; executing a recognition process based on handwriting input data corresponding to the accepted handwriting input operation when the reverse input mode is not set; reversing, vertically and horizontally, the handwriting input data corresponding to the accepted handwriting input operation when the reverse input mode is set; and executing recognition processing based on the reversed handwriting input data.