The region is not as tightly integrated as Tokyo though. There's a good chunk of people who commute daily from Shenzhen to Hong Kong through the electronic cust

The region is not as tightly integrated as Tokyo though. There's a good chunk of people who commute daily from Shenzhen to Hong Kong through the electronic customs but for most people, going in and out of the mainland is not that simple. The culture on both sides of the border is also very different. It's only anecdote but a surprisingly high percentage of my friends in Hong Kong have never set foot in Shenzhen (let alone Guangzhou) and vice versa (I live in Shenzhen). I've even had friends tell me they were scared of going to Shenzhen because they don't consider it "civilised" (which is laughable of course).