Processing a Work (Z) Visa application in Tokyo. Which office?

Hi

I'm currently living in Tokyo and about to take up a year contract job in China. When my Chinese new employer sends me the paperwork to be presented and my passport stamped for entry to China, do I perform this directly at the Chinese consulate in Roppongi or do I go to the new CVASC centre in Minato Tokyo?

Thanks in advance
Mike