So its a Win7 system 64bit, JP local with applocale, keyboard layout eng, no controller or any usb except mouse and keyboard.Just in case, keys are arrow keys, Z and X. beyond thqtm I doubt we will be able to help in any significant way unless you are a bit more precise about your computer environment, are you in JP local for example ?
Have like 50 other games all works fine with arrow keys and z,x.
The problem needs to be something like the left controller support thing but i m really out of ideas right now, so.. =/
edit: looks like even with a virtuell keyboard software like the one from windows itself, dont have any impact on the game