Transiting visa

Hi,

I would be flying to Shanghai from the UK, staying in Shanghai for 5/6 days and then fly from Shanghai to Tokyo (with a different airline) so it’s not a layover. Then staying in Tokyo for 4/5 days then fly back to Shanghai from Tokyo, to fly back to the UK with no stay over in Shanghai. Would we need a visa for this? Is the transit visa be sufficient? If so, how we can apply for it?