1. A character input method comprising: receiving a first interaction; displaying a first character in response to the first interaction, the first character being at least one of Korean consonants; receiving a second interaction successively after the first interaction; identifying a second character that can be formed by combining the first character with a character according to the second interaction, the character being at least one of Korean vowels; and displaying the second character by replacing the first character with the second character, wherein the first interaction comprises: a touch interaction input to a particular character area on a touch keypad; and the second interaction comprises at least one of: a draw interaction created when the first interaction occurs and then dragged in a first direction without releasing a touch and configured to input a preset group of vowels —, and |’, a draw-and-backtrack-flick interaction created when the draw interaction is dragged a distance in a second direction, and is moved in a direction opposite to the second direction and then is moved back a shorter distance in the opposite direction and configured to input a preset group of vowels ‘ , and ’, and a draw-and-backtrack-drag interaction created when the draw interaction is moved a distance in a third direction, and then is dragged back greater than a preset distance in a direction opposite to the third direction and configured to input a preset group of vowels ‘ , and ’ or ‘ , and ’, wherein the first direction of the draw interaction moves starting from a point in the particular character area to up, down, left, right and diagonal directions, wherein the second direction of the thaw-and-backtrack-flick interaction moves starting from the point in the particular character area to the up, down, left, right, and diagonal directions, and wherein the third direction of the draw-and-backtrack-drag interaction moves starting from the point in the particular character area to the up, down, left, and right directions.