Hi I currently hold a Vietnam passport. I will be travelling from Sapporo to Singapore

(where I am a Permanent Resident), transiting in Shanghai. I will reach Shanghai at 1635hrs and depart at 0000hrs, having a 7.5 hours layover. May I know if I need to apply for a visa transit or any visa for me to enter Shanghai city and leave the airport? If so what are the documents I need for me to apply?