Please help.

I am a Chinese citizen working in the US. I came to America on a student visa and my status was changed to working visa "H1B" but I have not yet traveled back to China to receive the official H1B visa on my passport. I am planning to return to China and would like to transit through Japan for a short-stay. I do not plan to return to the US. What is the best way to obtain an Japan Transit visa for my visit in Japan before returning to China? Thank you.