In the game we have only the options to change the action buttons, not the D-PAD. And I play with my computer, I'd like to use that standard: "a,w,s,d" for directional, etc, etc.

Do someone know how to change this?

Looks like that's only achievable via a third party program like AutoHotkey.

Tis a Japanese computer port. Not much expected, only the rare pleasant surprise.