1. A machine implemented method of displaying an animation image of a user model using fitting information, said method comprising preparing an animation program which when executed, causes a processor to perform displaying an animation image of a standard model; fitting the standard model to a user model by affine-transformation of three-dimensional coordinates at first target vertices of the standard model to three-dimensional coordinates at corresponding second target vertices of the user model to generate fitting information; and executing the animation program prepared for the standard model, by using data of the standard model fitted to the user model based on the generated fitting information to display on a display device an animation image of the user model, the step of fitting the standard model to the user model including: specifying pairs of the first target vertices of the standard model and second target vertices of the user model; dividing a distance between the first and second target vertices of each of the specified pairs into a predetermined number of divided distances; gradually bringing coordinates of the first target vertices of the standard model closer to coordinates of the second target vertices of the user model by affine transformation of each of said divided distances individually; casting a ray from a protruding vertex having a normal vector, of the standard model to the user model in the direction of the normal vector to set an intersection of the ray and the user model as a new vertex of the standard model; and generating fitting information based on the first target vertices, of the standard model, brought closer to the specified second target vertices of the user model, including the new vertex of the standard model.