Short time visit to China with German passport

I have German passport but am originally Chinese. I intend to visit my family in China for not more than 3 days. However currently I am on a business trip in Tokyo on a temp. visitor visa. During the weekdays it is very hard for me to free up time to visit the consulat myself. I have looked around but there seems no travel agency supporting application for foreign passport holders without residential permit. Do I really have to go there by person and also pick it up by person?
Thanks a lot in advance!