I still dont understand why pewdiepie moved to Japan to raise a family.
I can't speak for him, but I'm in the exact same situation he is, and one of the reason for which I moved here is because it's pretty much the safest place I could think of to have a family.
Of course it's also good for our jobs, the quality of life, we like the culture and the language and all that, but I won't make my children grow up surrounded by shitskins that hate them, and have to worry whenever my wife is outside after 5 PM. It makes sense for me to be here. It could've been other places, sure, I lived in somewhat safe places in smaller European cities as well, but since I have to move away from my home city, might as well go somewhere we enjoy.
Personally I don't find the "why did you move" question interesting, lots of people move for random reasons, because they know a guy, because they're doing a sabbatical, because of a girlfriend, because of studies, etc, the interesting question is "why are you staying here", which is a constant decision made year after year. Everyone got his own answer.
Drug use is incredibly taboo in Japan and is not usually talked about.
Yes and no, depending on the circles you're in, it's actually not taboo at all.
If you hang out with rebellious youth, hangure, fighters, or the general kabukichou/roppongi/shibuya people, you'll hear about them quite a lot. Some forums are also not shy at all on the topic.
The thing is that contrary to common belief, a lot of drugs are accessible and/or legal.
I can buy opiates on online pharmacies legally, I can buy cannabinoids vapes (analogues of THC) on Rakuten legally, Benzos are distributed like candies by doctors for "anxiety", you can find sellers of unregulated LSD (like 1D or 1P-LSD) on Twitter, other GABAergics drugs like Phenibut and GHB analogues are around and not illegal to do, kids love to do that pure DXM sold OTC and talk about it in school, it's legal go to pick psilocybin mushrooms in nature if you don't say that you knew that they were psychoactive if you get caught, etc.
What is super illegal and plain stupid to go after is the big ones that people that don't know laws go after because they're "famous" and "cool", like cocaine, meth, cannabis, or heroin.
The reality is that substance use and abuse is full of small subcultures depending on the category of substances and its use, and they exist like in any other country. You simply won't hear about it on TV shows or something because the government won't allow it. The book "NHK ni Youkoso" got into some trouble when it was published because the writer wrote about his DMT experience, and how he ordered the ingredients online to make it legally in his home.
Hell, until a few years ago 3-MMC was legal, party people were having a lot of fun with that.