Chinese visa for US citizen whose going on a 7day cruise (Celebrity) Shanghai ends in Tokyo

Leaving Chicago 10/7/16 via UAL w/ my husband both US citizen; arriving Shanghai 1:50PM 10/8/16. Our boat is leaving the port 10/9/16 7pm and the cruise ends in Tokyo 10/16/16. We're staying 6 more days in Japan. Our flight back to Chicago is 10/21/16 via UAL. Do we need to get China entry permit?