The problem is, most Japanese publishers do not want to support the PC locally. They also heavily favour DRM when releasing their games on the PC as they are totally paranoid about piracy. see Capcom now refusing to release certain games on the PC at all due to piracy -- while also conveniently ignoring the fact that piracy is rampant on the Xbox, PSP and DS (even locally).
So as GOG, so far has been only releasing games that are DRM free and that can be sold worldwide for one price, it's going to be near impossible to persuade Japanese publishers to release here. And that's after GOG have managed to get past the "language barrier".
Tantrix: PS.: I am no Otaku
I should hope not (or were you referring to the Western meaning of the word?)