Japan is just gaming the numbers here. Both with the conviction rate and with the homeless ratio.

https://www.examiner.org.hk/2025/01/17/the-invisible-homeless-in-japan/features/

According to this link, if you apply western metrics, Japan would have between 100k and 200k homeless. Which would mean Japan has 81.2-162.4 homeless per 100k inhabitants, while the USA has 221.7.

That would make Japan a bit better than the USA, but it's not that much of a difference any more.