A method implemented by a transmission device to communicate with multiple reception devices that respectively share a drawing area with the transmission device is provided. The transmission device transmits to the multiple reception devices vector-data ink data representative of traces of input operation detected by an input sensor of the transmission device. The method includes: (a) an ink data generation step of generating fragmented data of a stroke object, wherein the stroke object contains multiple point objects to represent a trace formed by a pointer, the fragmented data being generated per defined unit T, and generating a drawing style object; (b) a message formation step of generating messages including the drawing style object and the fragmented data; and (c) a transmission step of transmitting the messages.