Some games doesn't just support IME. Those games has native fonts, unless it is LOCALIZED. Some games that uses windows objects, such as textbox, they support IME. But in most cases, if IME does work, it will only display some ??? as a representation of the character/symbol. Just see what default font face does a game uses, so you may know if it does support east asian characters. i.e. Arial Unicode, MS Mincho etc.