I lived in Tokyo in 2006-2016, I was 26 when I was offered a 1-year internship in Tokyo, ended up getting a full-time job and almost 10 years decided it was time to move on.
Japan is interesting, couple points:
1) Samurai's, Geishas and Yakuza don't walk on the streets.
2) The language is not difficult, but the level of the language one needs to speak to be understood is pretty high. In English you could say "I eat" and
people would figure out that you might want to eat, but in Japanese you'd have to say the full sentence with all the details and stuff in the right places, otherwise it "doesn't match the pattern" and doesn't work.
3) It's convenient, sometimes too convenient, everything works, everything is on time. Things don't just break. Over 10 years not a single time I had to call any repairs nor "handymen" for example.
4) Japanese are slowly opening towards foreigners (very slowly), but what I found is that you're more likely to find a 60-year old grandpa speaking English
than a 20-year old person.
5) As a foreigner, it was actually much more convenient for me NOT to be fluent in the language - this way I could always get away with something, or ignoring the rules. If you're fluent they'd also expect you to behave and conform to the society...
6) Don't ask for permission - just do it and ask for forgiveness - usually the answer is no, but when you just do it, as a foreigner you get a lot of leeway.
7) DO NOT even think of working for traditional Japanese company - you'd have to conform to the stupid rules and stuff, if you're thinking of moving to Japan the easiest thing for foreigners is to become English teachers (but these days you'd need to be be native speaker).
City vs countryside are extremely different, Tokyo is simply a concrete jungle, not that different from any other major city (well except reliable transport and safety). In countryside people are actually nice and kind. In Tokyo - i've never even exchanged a single word with any of my neighbors.
9) Owning a car is pointless (especially in Tokyo) and expensive, getting a license is easy, if you can prove you've had your foreign license for minimum 3 months (and been in the country of issue for that time) then all it takes is 10 questions on written exam and a quick driving test at the track. (If you can prove one year of having a license then you won't need a "beginner mark" sticker.
10) Video games - yes, but nearly all games are catered specifically for domestic market, very few make it out and get released globally (in English).
Happy to do more of this, it's just a random spill, if you have any specifics let me know.