Japanese Citizenship and Passport?

I've been legally adopted by my Japanese stepfather months ago, now i have to file for a change of name and everything, they said I could also change my citizenship and passport if I wanted to, how do i do this?

i don't think you can automatically get Japanese citizenchip in this case acording to Ministry of Justis article. You may live in Japan and work without any restriction,so if you live in Japan 5years you may apply for permanent visa. After 10 years (max) of living in Japan you can apply to nutralize.

not nutralize
its naturalize :P

To make a long story short, I was considering adoption so I went to a Japanese consulate and was told that even if I were to legally adopt the child, I cannot pass on my Japanese citizenship to him. Now this was years ago so the rules could have changed so try check with your nearest consulate if you are living outside Japan.

I'm not sure but I don't think as an adopted child you can get citizenship, but rather a special visa such as "Child of a Japanese National"

I could be wrong too. If they (the Japanese government) said you can do it, then ask them.

You can get a dependent visa, it's not difficult to get in most cases.