1. An imaging device comprising: an imaging unit configured to image an object and generate image data of the object; a display unit configured to display an image corresponding to the image data generated by the imaging unit; a display controller configured to control the display unit to display an expression guide image in which at least a part of expression of a face in the object has been changed; an expression determination unit configured to determine similarity between the expression of the face in the object in the image corresponding to the image data generated by the imaging unit and the expression of the face in the object in the expression guide image displayed by the display unit; an imaging controller configured to control the imaging unit to continuously image the object until the expression determination unit determines that the expression of the face in the object in the image and the expression of the face in the object in the expression guide image are matched, wherein the display controller is configured to control the display unit to display another expression guide image at a time the expression determination unit determines that the expression of the face in the object in the image and the expression of the face in the object in the expression guide image are matched.