Japanese passport renewal

I am a naturalized US citizen (w/ US passport). I also have a Japanese passport which is about to expire in a few months, and would like to renew my Japanese passport. My questions are:

1. Japanese consulate in LA is where I'll be renewing. Would I need a koseki tohon or would I be able to use my current unexpired Japanese passport and pay the fee and just wait to receive? It has been 10yrs since last renewal and can't recall.

2. During the reapplication/renewal process, will I be asked whether I am a citizen of US or hold any other national passport?

3. Would I be able to renew my soon-to-expire Japanese passport, if I am a naturalized US citizen?

4. Is it possible for my children to obtain dual citizenship if they are beyond the age of 22yrs, and was born before I was naturalized?

Any input/answers are all very appreciated.

Thanks!!

Look up dual citizen; Japanese passport; bicultural;etcetera.

Basically, this issue has been covered before and the advice given is contradictory. It would be best if you did some research, rather than relying on advice from people replying to this thread.

You cannot renew your passport because you're not Japanese. You gave up your Japanese citizenship when you became an American.

During the reapplication/renewal process, will I be asked whether I am a citizen of US or hold any other national passport?

Not only will you be asked about it, you'll have to present a green card or US passport.

Is it possible for my children to obtain dual citizenship if they are beyond the age of 22yrs, and was born before I was naturalized?

This depends on when and where they were born. If they were born outside of Japan then you can forget about it. If they were born in Japan after 1985 then it's possible they already have dual citizenship.