My info is not the most up to date, so more experience people (Like MMM, Nyorin, James... etc), please correct this
I want to post this up, as info for people who want to stay in Japan. If you are reading this because you want to stay in Japan, pleaes read through this thread.
These are the legal ways for you to gain residency in Japan. If you don't have one or more of the following, then you cannot become a resident legally. Don't waste our time with stupid delusional questions.
To get permanent residency in Japan you will need
1. A source of income. Meaning a job, a job that is willing to sponsor you for your visa. This means a 4 years university degree from a recognized institute that the hiring company like, or special skills that cannot be acquired within Japan. Degrees from a degree mill or a non accredited university doesn't count....
2. Married to Japanese who want to reside there - I made this mention because a friend of mine married a Japanese girl thinking that it will also give him the right to live in Japan, except that the girl actually wanted to move to Canada so he is back in Canada now....
3. A business establishment - This I will need more info on. Its only something I THINK can qualify you to live in Japan, is to start a business. Its like immigration by means of investment. You cannot just claim to start a home office though, there is a requirement that you need to qualify for, and as far as I know, the starting capital is not a small amount, and you need a good plan to demonstrate how much income you will generate, how many jobs you will introduce to the market and such.. basically, $$$$ and a very well written business plan
Cultural exchange visa, student visa and WHV does NOT give you permanent residency, but can be considered a stepping stone. For example, if you are on a student visa studying neurology at Todai, and they decide to keep you to do research after you graduate from your PHD, thats totally different. That will be the same as getting a degree and getting sponsorship
EDIT: Update on point 3 above - found this info on Hiragana Times:
Visa Information - Visa for Japan
In order to start a business in Japan, you need to have an "investment and management" visa. After entering Japan with a short-stay visa and carrying out preparations to set up a company, etc, please apply for the Certificate of Eligibility before you leave Japan.
In the case of an investment and management visa, there are some important points to note: (1) you have to find a location for the company. If you combine it with your residence, it should have more than two rooms with at least one room set aside for company use. (2) You are also required to invest a considerable amount of money in your business. The amount should be enough to manage management policy, which is considered to be at least five million yen. Also, prepare the relevant statements to show this amount. (3) You will also need to examine the scale of the business and create a 1-year business plan.