1. An input device comprising: a receiving section configured to receive a plurality of characters input by an operation of a user; a confirming section allowing the plurality of characters received by the receiving section to be confirmed; a display section configured to display the plurality of characters allowed to be confirmed by the confirming section; a touch sensor configured to detect a touch point on the display section; and a display control section configured to confirm the plurality of characters according to a confirmation signal received from the confirming section and allow the display section to display the plurality of confirmed characters, wherein the display control section is further configured to identify, based on the touch point detected by the touch sensor through a double tap of the user, at least one conversion target character from among the plurality of confirmed characters, convert a character style of the conversion target character, allow the display section to display the conversion target character in the converted character style, confirm the conversion target character in the converted character style.