Well, now is the future, I live in Tokyo and my work involves "hacking virtual realities" and "artificial intelligences"... And I must say that it is quite less exciting than what I thought.
My hopes for the AI field are dwindling. The current tide of hype will probably culminate in a few mediocre services from Google/Facebook/Microsoft/Etc. The services will have serious downsides, the downsides will be downplayed by the marketing, everyone will begin to integrate with them, and as a result we will get more complex, unstable and invasive software.
I still have a lot of hopes for VR, since it's not widely available yet and there is room for creating fundamentally new things there during the adoption period. Hopefully, the ideas of Bret Victor will not go unnoticed.
He is living the dream :)
But a better question would be how was he able to live every nerd's wet dream? Japan does not seem to be making huge strides in AI at the moment so even if you are able to find a dev job in Japan it seems unlikely that it would involve robotics.
In Tokyo and Osaka, my understanding is that many IT jobs are in English. Japan is also probably one of the easiest countries in the world for IT/engineering workers to get a visa: have a degree and a job offer and you are set. I don't know how many robotics jobs are English, though (the guy I was talking to was Japanese and didn't speak English).
I think it's probably a lot easier to find a job like that than you think. The reality is, though, that the salary (especially if you actually want to live in Tokyo rather than Chiba, etc) will likely be shockingly low compared to US salaries. I think senior devs are going for the equivalent of around $80K these days. Possibly you can make up some of that with bonuses, though. I don't work for a Japanese company (and I'm not in Tokyo), so I don't know the details.
All the good Japanese engineers are already working for a big company and they are not likely going to change to a smaller one. For Japanese workers, security is usually the priority number one.
So yes, if you have a degree in STEM, it's really not that hard to emigrate to Japan. To know Japanese would open a lot of doors, but it is not mandatory if you have a good CV. Also, anybody can get a decent level of Japanese with two years of study.
On the other hand, you can probably make much more money in California, or even in London than in Japan. And also, the work-life balance in Japan is practically inexistent. When you sign a job contract with a Japanese company, they assume that you are giving your entire life to them. You are allowed to go home to sleep and bathe, but just because they are kind with you.
So yes, Tokyo has interesting things, but is not as amazing as we thought it would be. Also, there are no punks... everybody obeys like robots.