1. An image tagging device comprising: a first functional unit that generates a first image by changing a first region image corresponding to a first object related to privacy information in a master image stored in a first memory and thereby removing the privacy information included in the master image; a second functional unit that acquires the first image generated by the first functional unit and generates an operation request image by changing a second region image corresponding to a second object that is not to be tagged in the first image; an operation request image distributer that distributes the generated operation request image to a tagging operation terminal device over a network; an image tag information receiving unit that receives image tag information, as a response to the distributed operation request image, from the tagging operation terminal device over the network; and a tagged image generator that generates a tagged image on the basis of the master image and the image tag information.