INFORMATION PROCESSING SYSTEM AND ELECTRONIC PEN

An information processing system includes an electronic pen, a position detection unit configured to detect the position of a pen tip of the electronic pen and to acquire positional information indicating the position of the pen tip of the electronic pen, a modification ID storage unit configured to store a modification ID for identifying modification of the position indicated by the positional information, a modification ID updating unit configured to update the modification ID, and a reception device including a storage unit and a registration processing unit configured to register the modification ID stored by the modification ID storage unit and the positional information acquired by the position detection unit in the storage unit as associated information.