An image generation device according to an embodiment includes a synthesis unit and a superimposition unit. The synthesis unit synthesizes an overview image for a virtual viewpoint that is provided in a manner to look in a direction of travel of a vehicle so as to include at least a portion of a side of the vehicle based on a taken image that is taken by an image-taking unit that is provided on the vehicle. The superimposition unit superimposes a plane image where a vehicle has been caused to be planar, at a position of the vehicle on a road surface, on an overview image that is synthesized by the synthesis unit.