1. A character input method for displaying an alphanumeric character when the alphanumeric character is input to a mobile station, the method comprising the steps of: determining whether a character input event occurs for the alphanumeric character; checking a visual character theme for adding an animation effect corresponding to the visual character theme to the input alphanumeric character when the character input event occurs; loading a background image corresponding to the visual character theme; loading animated character data according to the visual character theme in response to the character input event, the animated character data being the input alphanumeric character with the animation effect added; and displaying the animated character data, wherein the input alphanumeric character implemented by the animated character data is drawn by tracing strokes of the input alphanumeric character on the background image, and wherein the animated character data is displayed on a screen of the mobile station, the screen having at least, in order from a bottom, a background layer displaying the background image, a character effect layer displaying the animation effect, and a character input layer displaying the animated character data.