There has never been any requirement to wear masks in Japan, but strong advise and until recently it was followed 99% of the time. Now the advise is to wear on transportation and in shops etc but ok not to wear outside if not in close proximity to others.

I would say its still 95% masks on, but becoming little by little more relaxed but social pressure is to wear, and it certainly is more socially accepted to wear one, you don't make
others uncomfortable