Donald Richie in one of his collections of essays wrote about how the "narrowness" of the Japanese home forced people to seek places to relax elsewhere--a favorite snack or kissaten (coffee shop). These, he wrote, were extensions of their home.
I'm sure I have misparaphrased that, but I couldn't help thinking about what the Japanologist had written while I was wandering the streets of Hong Kong. Streets were like dry riverbeds between deep ravines, the walls of which were formed by impossibly tall, impossibly slim apartment buildings.
Google "small Hong Kong apartment" and you'll find photos of insane living conditions; apartments no bigger a four-mat room in a Japanese home.
Decades ago, a girlfriend of mine went to Hong Kong to help her friend with her flower buisness. "They slept on the kitchen floor!" she told me when she returned. I couldn't quite picture people living in conditions so cramped, but now that I've been to the city, I can.
Richie wrote of the uncomfortably cramped living conditions of modern Japanese, but in reality it isn't all that bad. My 90-square-meter, 4LD here in Fukuoka would probably house three to four middle class families in Hong Kong. Perhaps more.
Another thing, you can see further than fifty meters here in Fukuoka. Visitors to Japan from HK must feel liberated being able to just breathe the air while they're here.