Considered a transit? Can I apply for the 144 hour free transit?

Hello,

I currently have the "return" part of a round trip ticket that I bought in the past. So in a sense, I have 1 one way ticket from the US to Shanghai. Currently I have no visa to enter china. However, I am planning to go to Japan before heading back to china (will apply for visa to china in japan). So it would be 1 way from US to Shanghai ; then hopefully visit my family in shanghai for a few days if I get the 144hour free transit stay thing ; then use the roundtrip ticket (which I will purchase before arriving to china) from Shanghai to Japan ; apply for a visa to china in japan ; return from japan to shanghai again. Is this ok to do?