If you hold the through flight tickets from Tokyo to Shanghai, Shanghai to the next destination and booked seats, you don't need a China visa for the 4 hours transit in Shanghai.

However, if you want to apply for a China transit visa from the embassy in Tokyo, please provide your a valid visa from the destination country/region and tickets for connection flights, your passport and one completed visa application form affixed with one passport photo.

thanks for the response.

the problem is, that I'll have to check out in Shanghai and then check in again, because there are two different airlines with which I'll fly, so I need I visa, I guess?

do you mean with"valid visa from the destination country" the country to which I fly from Shanghai?

Mr.Sara, German nationals are exempt from a visa to transit in Shanghai for up to 48 hours (go out of the airport is allowed), therefore, please don't worry about the check out and check out.