Kenzo99
That said, you will run into bureaucratic nightmares. I could go on for pages about firms that won't allow developers FTP access, ones that won't allow you to set up WordPress (they're not an official vendor), firms that want people to sign up for their email newsletter, but by phone because they think the Internet is scary and they don't want personal information put into their website, and other stuff that to this day I still sort of don't believe.
But you'll learn how to be patient, get through those situations, and build either a client base or find a job somewhere that makes sense. Because there are great clients and good companies to work for here. It takes time, but if you learn the language and have solutions to problems people have and can show some examples of those solutions in a portfolio, you'll start finding work. Webdevs are a dime a dozen, but good webdevs who can seamlessly work in English and Japanese will always have work here.
This article talks about the many ways public key can be circumvented, but offers no insight into a mathematical breakthrough. Thus, there will remain a way to encrypt your data, you just need to make sure your keys will always be safe.