I heard that a startup which I don't know hired Chinese when I was working in a startup in Tokyo. I also found some non-Japanese speaking people were working in OpenSource cafe. http://www.osscafe.net/en/

I'm going to give you some links that would be useful.

Tokyo based Seed Accelerator: http://onlab.jp/

Social Hiring platform: https://www.wantedly.com/

Japanese AngelList-like service: http://creww.me/