1. A character recognition method for recognizing a character printed over a background pattern on a valuable medium, comprising: acquiring a character image captured by capturing the character printed on the valuable medium; evaluating a degree of similarity between the character image and each template image, the template image having been obtained beforehand by capturing each character that had a possibility of appearing on the valuable medium and of which background has been filled evenly; and determining that the character corresponding to the template image showing the highest degree of similarity at the evaluating is the character included in the character image.