I wonder if that's possible in Japan for a black person
I'd assume so, though I'm not aware of any statistics that'd catalogue police action there by skin color / ethnicity, not official, not third party.
I'd think a formal or business casual attire, with proper grooming, is a rather international signal that you're vaguely alright in your ways.
Anything specific you reckon otherwise for?
The author of the article is a black woman, so... maybe not.