The Japanese version contains mostly-finished data for the English localization of the game, which was still unfinished by the time it was released in Japan. By using a hack to trick the game into running in English, most text files and voice lines will be in English, and the controls will change to reflect the NA/PAL standard. However, the cutscenes will still be the uncensored Japanese animations with their respective original lip-syncing, and Roxas will use older voice clips from the original Kingdom Hearts II instead of the final English release which uses voice clips from Ventus from Kingdom Hearts: Birth by Sleep instead.

In the original Kingdom Hearts II on PlayStation 2, Kairi's underwear can be seen by maneuvering the game's camera angle. This was removed in the HD version.