I'll preface this with I'm a Chinese American with relatives in China, for you know, credibility.
The gaming culture there is wildly different from Western gaming culture. There are almost no console players in China with an almost non-existent market for it. Most of it revolves around Internet cafes and PC gaming.
There's also the question of language, and learning Japanese is far easier than Chinese. But if you do learn Chinese, Japanese will come a lot easier because of character meaning similarities.
My recommendation would be Japan first, and then China. If you have any additional questions, PM me!