1. A non-transitory computer-readable storage medium storing computer-readable instructions for inputting characters by using a pointing device having at least one button and capable of pointing at a set of coordinates on a screen of a display device, the stored computer-readable instructions configured to: display a character input key image associated with a group of characters on the screen; detect the set of coordinates on the screen being pointed at by the pointing device based on a signal from the pointing device; detect whether or not the at least one button is operated; display a character on the screen as an undetermined character in a cyclic order from among the group of characters associated with the character input key image each time the at least one button is operated while the set of coordinates on the screen being pointed at by the pointing device is detected to be within the displayed character input key image; determine whether or not the detected set of coordinates is within an area other than the displayed character input key image associated with the displayed character that is the undetermined character; and display the undetermined character as a determined character on the screen in accordance with the determination that the set of coordinates pointed at by the pointing device is within an area other than the character input key image associated with the undetermined character displayed on the screen, wherein the determination of whether or not the detected set of coordinates is within an area other than the displayed character input key image is done with reference to the detected set of coordinates and character input key image layout information representing a display position of the character input key image on the screen.