Part time work in Japan

Hi there people.

Right, basically, I'm wanting to move to Japan. I have no degree, but I'm very well educated. I'm going in March or April on a working holiday visa (UK citizen). I'm hoping to gain sponsorship in some field or other by the end of my year there, and remain thereafter.
I figured that, since my English is good, and I have some experience of teaching it conversationally (though no formal qualification), the easiest thing to do when I get there is teach English. However, I don't really want to do that, certainly not full time. I'd like to do that part time and mix it up with some other work (though I don't know quite what). [How easy is this to do?]
I'd then like to get sponsored to live and work doing whatever it is besides teaching. Something like DJing, fashion stuff, business... God knows what, just something a bit different, preferably in the public eye. I figure Japan's the place to do that, especially due to the special treatment I receive being a lovely young gaijin.

So I'm really just wanting some general opinions and observations from people who know their stuff. Am I a hopeless dreamer? Or is my lack of specificity actually opening up more opportunities? I guess you need to know me to know how realistic this all is, but I'm certainly confident in my own ability to succeed.
Do people succeed in this kind of thing often?

I know I've been very vague, but whatever you have to say will be most appreciated.

Thanks.

Working Holiday Visa is a special arrangement between some countries, allowing young people (thus age limit) to travel extensively overseas (in your case Japan) while giving the travelers some way to earn some pocket money along the way to help with travel expenses. Therefore, there is a max limit (is it one year for UK citizens?) after which the normal working visa requirements apply if you want to work in Japan.

So, the working visa requirements (those are Immigration requirements) would be either (1) a bachelor's degree, or (2) several or more years of work experience in the relevant field (meaning you need work experience in the field you are trying to find employment in), which can be three years in case of English teaching jobs.

So, if you want to teach English in Japan BEYOND Working Holiday Visa, if you already have solid, full-time English teaching experience of three years or longer, or if have two years' experience and you want to spend the initial one year in Japan working as an English teacher, you might have a chance.

I have heard of someone (his blog webpage was mentioned also somewhere) who initially came to Japan on Working Holiday Visa, and somehow managed to stay beyond that, I think he was an English teacher, and the employer liked him/his qualifications so much that they somehow found a way. (Sorry I don't remember the name or the link) But it is considered an unusual case.