Wondering about Nikkeijin visa

Hi all, I am a third generation half Japanese American; my paternal grandparents were born in Japan. I am graduating from high school this year and am studying Japanese and recently passed N3 of the JLPT. I'd like to work in Japan in the future after university (Japanese studies major). If I were to lose my job or have to quit on a work visa, I'd have 3 months to go back to the US, and I really don't want that mess. There isn't much info on the web so I'd like to know if anybody here has had experience or knows anything about the "Nikkeijin visa."

I understand that third generation Japanese descendants can be eligible for a teijusha/long-term resident visa, but since my grandparents renounced their Japanese citizenship and became US citizens, would this make me ineligible? They were US citizens at the time of my birth, and I think they were at the time of my father's birth, too. Would a joseki-tohon count the same as a koseki-tohon in applying? My grandfather has passed away and my grandmother is alive, but from what I understand citizenship can only be passed through the father's side under Japanese law.

Thank you.

Citizenship can now be passed maternally, they changed that law back in the 80s. However there was a window, long passed now, in which to retroactively have the new law apply. It probably doesn't have any bearing to your situation, but just thought that I would clarify that point.

I am a sansei.

My daughter, who is hafu, is currently living in Japan and working. She is in the final stages of getting her long term residency visa similar to what you desire.

The process has been fairly straight forward.

Her Japanese lawyer had her gather all relevant documents...you will need to have EVERYTHING in original form that links you to your grandparents.

From my side of the family (my mother is nihonjin), she obtained her original birth certificate, my original birth certificate, my mother's japanese birth certificate, my mother's Koseki (my mom had one from the 1950s and my cousin got an updated one from the local ward office), my mother's marriage certificate to my father (he was a nisei), my marriage certificate to my (now) ex-wife who is my daughter's mother and copies of my mother's USA passport, my USA passport and my daughter's current passport.

From my ex-wife's side of the family, my daughter obtained her mother's birth certificate.

You may also need a financial guarantor in Japan and one or two people who will write a letter on your behalf attesting to your character and so on. My cousin did those things for my daughter.

All of that, filling out some forms, and about Y80,000 later in lawyer's fees, my daughter had the lawyer submit all of the paperwork about 45 days ago, so she is waiting to hear back.

This is all to prove lineage of course and the government is insistent upon original docs so you may want to start accumulating those, I had to search my mom's stuff, their safe deposit box, etc. to find all of the appropriate docs.

Hope this helps.

Stan