Adoption by Japanese citizens,

I had a theoretical question that I am having a hard time finding the answer to. If I (a 19 yo US citizen currently living in the US) were to be adopted somehow by two upstanding, financial sound Japanese citizens currently residing in Japan that I have no actual blood relation to, how possible would it be to obtain residency status or even Naturalization?

http://www.moj.go.jp/ENGLISH/information/tnl-01.html

If you look at Article 8, (2) - you would have to have been a minor according to the law of your country when you got adopted - so 19 might be a bit late?

If you were adopted, which is highly unlikely in your situation, you could get the equivalent of a spouse visa. That visa will allow you to live and work here without restriction.

I couldn't imagine the adoption agency taking your application seriously if you go ahead with this.

Ah, thanks. I assumed as much but since the legal age in Japan is 20, I thought it would have been a possible interesting development if the adoption process was still possible.