A writing device includes: a voltage application unit that applies a voltage to a display medium including a first display layer, second display layer and a photoconductive layer; a first obtaining unit that obtains image data showing an original image; a controller that controls the voltage application unit and the irradiating unit to cause the display medium to show an overlapped image including the obtained original image and an overwritten image overwritten on the original image, the overwritten image including a point corresponding to the location shown by the location information stored in the storage unit.