FWIW there are definitely homeless people in Tokyo. Under a lot of overpasses in the affluent Shinjiku area, you'll find many homeless people living long-term. I was there as recent as last year and I wouldn't say it's nonexistent. :) Definitely an order of magnitude less than any major US city, however.

https://www.huckmag.com/article/yusuke-nagata-photographer-d...

https://metropolisjapan.com/tokyos-homeless/