A question about "Japanese only" signs in Japan?

As a retro video arcade game fan, I’ve been thinking of visiting Japan at some point in the future if and whenever this covid crisis gets under control. I’m quite familiar with its culture, etiquette, and people.
Or at least some elements of them. I’ve heard stories about some areas having signs reading “Japanese customers only” or Japanese only” kind of thing. If and whenever I visit Japan in the future, where can I expect to find these signs and therefore not wander near those areas, and do I need to worry about not being allowed in the video arcade game centers as an American foreigner? I’m doing a lot of research on Japan as I find the Japanese a very interesting people and a fascinating country.
Do I need to worry about being kicked out of the game centers on the basis of being a foreigner assuming that I follow the rules well and behave and speak some of the language?