1. A storage medium storing an animation image generating program which is run under the control of a computer system, the animation image generating program comprising the steps of: controlling selection of specific vertices of a standard model and a user model; providing control such that first target vertices are associated with second target vertices where the first target vertices are the selected specific vertices of the standard model and the second target vertices are the selected specific vertices of the user model; providing control by arithmetic means such that coordinates of the first target vertices approximate to those of the second target vertices, to generate fitting information; and animating the user model based on animation data of the standard model and on the fitting information.