1. A non-transitory computer-readable storage medium recording an image processing program for causing a computer of an image processing device for processing a captured image of a subject captured by an imaging device to execute: a captured image acquisition of acquiring a captured image; a virtual camera direction determination of determining an imaging direction of a virtual camera arranged in a virtual space, such that the imaging direction is changed in conjunction with motion of the imaging device; a specification of specifying, in information for performing predetermined image processing on the captured image, a particular piece of information determined according to the imaging direction of the virtual camera determined in the virtual camera direction determination; an image processing of performing the predetermined image processing on the captured image acquired in the captured image acquisition, by using the piece of information specified in the specification; and a display control of causing a display device to display the captured image subjected to the predetermined image processing in the image processing.