The fonts that start with @ all come out sideways, find the other one that has the same name but doesn't start with @.
Also, if you will be taking any Korean input and drawing it, you have to use
font_add() for the font (there is NO WAY the entire Hangul character set can be on a texture page all at once), and
keyboard_string won't work. See
this example (it's GMS 2, but the concept works in GMS 1.4 the same way).