I lived in Japan for about six years on and off, and at first I'll be honest I loved it. If you come from Europe, EVERYTHING is different and it really proved a delightful distraction from my depression. The road signs, the cars, the houses, the food, the vending machines, the restaurant chains, EVERYTHING is different. It kept me interested for several years but I struggled with the language despite paying for private lessons. At six years it seems to be the point where people decide to either marry and make a life for themselves or throw in the towel, and I hate myself for saying I threw in the towel. Things that had seemed charming at first - like people staring at me everywhere I went because I look 'different' - had begun to get on my nerves - I felt like at least in Tokyo, oh COME ON, you must have seen a white person on the train before. Not knowing the language means you always live in a certain bubble as someone else has said, and you can kind of drift through various English Teaching jobs (or at least you could, I heard the major ones have gone bust which might make it harder) or work as a 'model' or 'extra' in TV (did that part time, lots of fun, not enough to live on) or even get into QA for the English speaking market in video games (Square Enix and Koei both hire English speakers, or did).
There's a comic there called 'Charisma Man' which also documents the bizarre transformation that western men make as they walk through the gates at the arrivals desk at Narita airport and suddenly find themselves irresistible to women. Sadly it doesn't work the same way for women. But plenty of Japanese girls are keen to give a 'gaijin guy' a try to tick it off their bucket list, so it can be good fun, if shallow.
I totally enjoyed my time there, until I didn't, and then I left and went somewhere else. I would tell him that he should give it a try on a one or three year visa, but I wouldn't expect to live there permanently - I know a few men who do through marriage but it's very complicated - they don't have rights to vote, for example, and if their partner wants a divorce, they're basically going back home, is my understanding. I know only one person who followed the whole thing through, renouncing his American citizenship (I don't think you can have dual nationality, but this is all a long time ago) and became truly Japanese. It was an epic effort and very much the exception to the rule as he was so bloody minded about doing it.
Obviously just my personal point of view/experience but personally running away from my problems and travelling really boosted my mental health for over a decade. I was actually contemplating ctb alone in my crappy apartment, after I'd lost my job etc, and decided instead I would go travelling, since I had nothing to lose. Sadly now chronic illness keeps me pretty much housebound with nothing to distract me from my miserable existence. But if you are young and fit, I say do it, but leave the gate open to return but it's a very rare person who can settle permanently somewhere else if they don't have to (because of war or persecution or whatever). Home calls you after a while. I didn't think I was that kind of weak person, but it turned out I was.
