In recent years Japan's immigrant population increased by 500 to 1000 people *every single day*.

Many of them end up in hospitality, especially in touristic places, due to different reasons, but very importantly, immigrants from south Asia generally speak English fluently, something Japanese people rarely do.

I've seen plenty of "japanese" restaurants in Shinjuku where not a single member of the staff was japanese.

Another place where you're gonna see plenty of immigrants are all convenience stores.