Whether visa is required for cruising to Japan, Shanghai, Korea, Taiwan, and Hong Kong?

Hi, we are due to travel to beijing in april, staying 1 night in the holiday inn hotel before joining the Sapphire Princess for 14 nights - sailing to Japan, Shanghai, Korea and Taiwan before leaving the ship in Hong Kong (we will be going staight to the airport and flying home ) do we really need to buy the entry to china for this holiday???? Many Thanks
John and Eileen Hickling