Moving to Japan from Scotland/UK

I'm 22 years old, female and studying towards a HNC/D in interactive media.
I'm currently learning Japanese and I won't be ready to leave for japan for at least 2-3 years.
By the time I'm ready to leave I will be a qualified website developer.
Therefore what steps should I reasonably take towards getting to japan, getting a job and eventually becoming a citizen / aiming for japanese citizenship?

Are you fluent in Japanese? If not, it would be wise to go to a language school first, preferably in the area where you want to find a job and settle down.

May I ask whether you've already visited and spent time in Japan? I wonder why you're thinking about Japanese citizenship at this stage...

Also, unless you're completely fluent in Japanese and have web development skills and experience that puts you above native Japanese people seeking similar work, your best chance of work is likely to be teaching English. It's not impossible that you'll find work in web design but your options are going to be far far more limited.

And an HND unfortuantely isn't equivalent to a bachelor's degree, which is what is required by Japanese immigration. To answer your main question about the steps you need to take, I'd say that you should work towards a degree first and then consider emigrating to Japan.