There are countries in the world where homeless are pretty good hidden, by means of extreme expensive welfare, or are moved away from big cities, or at least touristic centers.
I have no idea in Japan. As I was there I saw extremely poor people (deduced from cloths and lack of hygiene) I doubt they had an own house. Even worst, I saw middle-class neighborhoods that I would associate with a favela in Brazil (albeit very clean and organized, each flat was smaller than a space in Rio.
Yes I think Japan does this as well. For example in Shibuya Miyashita Park, a recent traveller would find a nice mall here, but not too long ago it was a genuine park, one full of homeless.
The government pushed away people with nowhere to live to who knows where and built a luxury mall. All the tourists visiting assume Japan has no homeless.
A shrinking population like Japan's also changes the supply/demand curve in favor of people looking for housing options. That's probably a major factor.
I have no idea in Japan. As I was there I saw extremely poor people (deduced from cloths and lack of hygiene) I doubt they had an own house. Even worst, I saw middle-class neighborhoods that I would associate with a favela in Brazil (albeit very clean and organized, each flat was smaller than a space in Rio.