If you are on PC, there won't be any problem, I think.
On console, however, you could face this problem: Japan has PAL, I think (unlike China and Korea, which have NTSC, like the US). So playing the US-NTSC version on a PAL console and TV doesn't work.
Edit: Ah, forget about what I wrote there. China has PAL, Japan has NTSC.
So apart from any region lock - which the game does not have. to my knowledge - you'd be fine.