There are many of these schemes not only in China and Japan, there are many of them everywhere. Nowadays, many come from Singapore, usually related to cryptocurrency.
Quite a few of these schemes are based in Russia. Beautiful words, marketing and the hope that you will get rich this time leads people straight into this trap. And of course, financial illiteracy does its job.
Dropping names of country where scam originated is not really good but anyway this is the life of anonymous. Anyone are free to scrutinize without exposing identity.
Scams really come from all over the world. Mostly scammers come from most corrupt country. Scammers were just like being encourage from those countries seeing unsystematic leaders that are corrupt. They just follow what leaders do and this is why others are very innovative creating their ways on scamming. Old school tricks still effective.
Try to.post here that you will buy bitcoin and many users will going to pm you trying to scam you. Some of them are idiot scammers.
There are statistics showing which countries have the most scams. This does not characterise the people living there in a bad way. Although from the point of view of ignorance at the expense of which any scam lives, these countries do lag behind to some extent. It is ignorance that allows scammers to deceive people who are too lazy to learn. It is these people who become the first victims of any scam.