Storage device

Disclosed is a storage device which is provided with: a connection terminal for exchanging data with another device; a first storage means capable of storing a still image file received from the other device by way of the connection terminal; a second storage means for storing a synthesis data file which is used when predetermined information is synthesized in a still image; and a control means for performing data processing. When the still image file is stored in the first storage means, said data processing is performed in such a way that the predetermined information, which is based on the synthesis data file stored in the second storage means, is used to generate a synthesized still image file capable of displaying a still image that has been synthesized with a portion of a still image displayed by the still image file, and to store the synthesized still image file in the first storage means.