The world is full of amazing places to live, but no place is perfect. When we visit a destination, we only get to scratch the surface of it, we only get a glimpse of the cultural heritage, the historical background and the social or religious traditions of it. By all means, we can't but live a positive experience, most of the times.
There are, however, several, sometimes striking differences between visiting and living, which are difficult to grasp unless we've been on both sides of the fence. Let's see what are the challenges and advantages of living in Japan.
Earthquakes are part of life. I think this is the main thing to fully realize and be aware of, be it a short visit or a long stay. Earthquakes of minor intensity are recorded every day, but the majority of them aren't even felt by the most of population. Some earthquakes, instead, can be quite an experience. We all learn to live with them (to the point that we don't bother getting out of bed), and more often than not no fatalities are reported. That said, don't even consider Japan if you freak out at the faint idea of experiencing a level 3 shake (which is considered low here).
People are not often nice. It applies more to big cities than small ones, but, while tourists can experience only the best of Japanese hospitality, being helped and welcomed and greeted everywhere, residents in a big city often have to deal with hurried workers who are only focused on getting to work on time, no matter how. Rush hours see hordes of people bumping into others without apology, people squeezing themselves into packed train cars not caring for others, and such. If you have faith in people, such a thing will be challenged and crushed several times.
Personal space is lacking. When in cities like Tokyo or Osaka, everyone can't but notice how heavily populated they are. This can have a big impact on the quality of life of all those people who wish to move there. Unless you come from already densely populated cities, if crowdedness doesn't suit you think about choosing a quieter, smaller town for your living experience. The same applies to physical space, a resource that is cherished and optimized, but in the sense that empty spaces are a mirage. As a tourist, you will immediately notice it in the small size of your hotel room. So, if you are used to having all the space around you that you so wish, keep in mind that in Japan you'll have the feeling you're living in a shoebox.
The urban landscape at night seen from above
Visa. While foreign visitors can relatively get into the country easily, those who want to come and live in Japan have to demonstrate they already have a job waiting for them so that the process is less painful. Usually, for a visa, you would need a sponsor that in 90% of the cases is your employer, but many employers wouldn't take you unless you already have a sponsor and/or a visa. A visa-ous cycle, if I am allowed a pun. Visas also are issued depending on the job, and based on that their validity period is different. As a foreign resident wannabe, be prepared to several trips to immigration (with paperwork). European citizens realize how great being in the union is only after trying to move to a place that requires visas.
Language is key. Don't give for granted that everybody can speak English. Even in the big cities. It's OK when you are only visiting for a short time, as you probably won't run into anything that requires serious talk. But when you live in Japan, you'll inevitably need to explain a problem in detail, like a health related issue, and basically you need to be able to communicate not just about what food you like. Motivating yourself to learn the language can come handy, especially for more remote towns, where even all written signs are only in Japanese. Plus, speaking Japanese gives the advantage of being able to integrate more in the society.
Interactions can be frustrating. Japanese culture is very different than any other culture I know. From the perspective of a tourist, all Japanese habits and traditions can look just weird, or entertaining, or interesting, or hilarious. But after months or years of exposure to those habits, non-Japanese may start to get frustrated: people prefer to ignore others in most circumstances, with often comic or rude outcomes, as they think any interest in others might be interpreted as invasive or inappropriate. People are afraid to speak up, speak their mind out, criticize because they don't want others to think they're trying to impose themselves or look superior. People are shy, they like privacy and anonymity, as being pointed at or being exposed would put them in the center of all the attention. Also, interactions are less spontaneous, in general, and socialization is limited. It's a mindset that embraces every part of a Japanese life. Practice your zen and breathe, and always remember that just because you're used to doing things in a different way, it doesn't mean everybody else should adapt to your way.
Sushi at all hours. No other place in the world can give you sushi as good as the sushi in Japan. Eating sushi in any other place outside of Japan will just end up in disappointment. This country masters the art of raw fish dishes, and knowing that one can eat sushi every day is already a good reason to move to Japan. Same goes for ramen, the noodles in hot soup that in their broth hold the identity of a whole region. This country will spoil you with its food for sure. Tokyo alone has something like 80,000 restaurants of different cuisines and the highest number of Michelin starred restaurants in the world. Foodies of the world, this is your place.
Sushi and fresh fish
Give up the noisy habits. After living some time in Japan, every foreigner realizes how loud they were before. Okay, there are shop clerks shouting offers and sales with megaphones, trains, the traffic. But, as a private citizen, the Japanese are very, very silent. It would be advised that anyone trying to move to Japan behaved accordingly: no loud chatting (with the exception of drunk workers in the evening) and no talking on the phone in trains or buses, and no ringtones. And while you're at it, no public display of affection. But there is one thing that is designed to make noise in Japan, for privacy reasons: the phone's camera.
Holidays are stressful. Everybody seems to be going where you go, at the same time. The truth is that there are people everywhere, every time. Tourists can enjoy attractions and can do their sightseeing during the week, while the others are working. As a resident, you'd have to rely on weekends and holidays like everyone else. Because the Japanese love the fact that everything lasts for a short time, and because the days they can take advantage of such impermanence are counted (that is weekends only), in the end it really feels like the entire city is going to watch that very same firework show you planned to check out, or is going to the very same island you chose to spend your long weekend in. It sounds discouraging, and often it is, but it's one of the challenges of living here.
Crowded spots in Tokyo and temples for festivals
Last but not least, several other indicators that need consideration are safety (it’s so safe here that expats experience counter-shock when they leave Japan), excellent transport, great service, the convenience of finding anything one needs, insane shopping, gadgets, women in kimono, endless occasions for traditional and cultural experiences, but also high cost of living, heavily urbanized areas, resistance to open-mindedness, a slight discrimination and prejudice towards foreigners, in spite of the internationalization claims.
I think anybody can take up the challenge to live in Japan, either short or long term. Just allow yourselves more flexibility and practice what it is to be in other people's shoes.