1. An information terminal, comprising: circuitry configured to detect an image file; detect a face image included in an image of the detected image file; calculate an amount of feature of the detected face image; compare the amount of feature calculated with amounts of feature of different face images which are already calculated and classified into groups; calculate similarity values between the detected face image and the different face images in the respective groups; determine average similarity values of the respective groups, each one of the average similarity values representing an average value of the similarity values associated with a corresponding one of the groups; determine minimum similarity values of the respective groups, each one of the minimum similarity values representing a minimum value of the similarity values associated with a corresponding one of the groups; classify and manage the detected face image in a first one of the groups corresponding to an average similarity value that is the highest among the average similarity values and that is greater than a first threshold; associate the face images in a second one of the groups with the first one of the groups when the average similarity value of the second one of the groups is greater than the first threshold and the minimum similarity value of the second one of the groups is greater than a second threshold; and display at least one image file, which includes a face image classified as the first one of the groups, on a display screen based on a result of the classification of the detected face image.