Registered address versus Koseki?

This is kind of a long and twisting story so I am going to try and keep it short.
My daughter in law with help of a distant cousin was able to apply and receive a copy of her Koseki and some supplemental information a year ago.
It showed her home address when she was born and it showed that the family still was using that address as late as 2014. I was told that you can put "any" addresses on a Koseki as long as it is a real addresses.
Next the Cousin called a phone number for that address and the person that answered said the daughter in laws family had moved away a long time ago. The cousin said "I am confused this is their registered address I don't know why they are not there". I asked the cousin what that meant and I never got an answer.

So .... Do Japanese citizens have a registered address, maybe for drivers licenses , voter ID or taxes something like that?

Thanks Alan

Do Japanese citizens have a registered address, maybe for drivers licenses , voter ID or taxes something like that?

Japanese residents, regardless of nationality, do.

Thank you for the reply.

Thats interesting! We are trying to contact the family and someone answers the phone saying the family we are looking for moved away a long time ago. However that address is shown as their current address.
Hum....

Do you have any other details about registered addresses? How often are they updated? If you move do you have to re-register right away? Could this be something that they don't care about and never updated their addresses?

Thanks again!

The "current" address is kept in the basic residency register, not in the koseki.

So basically you are trying to contact the family? Be ready to be disappointed; that may well prove impossible. Google "find someone in Japan" or something, and you will see.

There is no official way for you to obtain their current address or other contact information; evzn if you manage to find the municipality where they are registered, they will probably refuse to give you the address, for obvious privacy reasons.

Thanks Firas!

I am only going by what the cousin wrote. This is why I am trying to get another opinion or explanation on how this all works. I understand the address on the Koseki is the same as the registered address according to the cousin. So I am not sure why she mentioned registered address then, if she can't access that. I know the office in Aomori where she requested the Koseki had called her about obtaining supplemental information. I don't know if she was able to slip in a question and they told her. Sadly parts of the story seem to be missing.

I know about about the family reunions. The only one I have personal experience with with another cousin of hers when she finally got a hold of her mother. It worked out but it didn't go smoothly. She had written letters and they were returned. finally she found her mom and half sisters on twitter and spent a day or two writing until she agreed to meet her.
The daughter in law does have photo's with who we think is her grandmother up to age two. So there was contact with her for two years, until she left Japan.

Thanks again!!

I don't think it's impossible for your daughter-in-law to find her parents or siblings if they are still on the same koseki as hers, although it may be difficult depending on the circumstances. My short answer is that your daughter-in-law should contact by herself the office in charge of her koseki for more details.

Now, here is my long answer.

Koseki: You don't resister phone numbers on a koseki. This is a family registration that help find where you're rooted at. Typically, the address is the home you lived when you were born, or people may change that address when they establish a different household such as upon marriage. The address on the koseki is the address required when having official IDs issued such as passports and driver's licenses. Official IDs are used for a great variety of things and are to be renewed every decade or so, so it's difficult to abandon a koseki address for good and still maintain a normal life in Japan. But you don't have to live at the koseki address at all. It could even be an address where a house no longer exists. As long as you have access to the koseki, you can do almost anything.

Juumin-touroku (residence registration): You don't resister phone numbers on a juumin-touroku either. The juumin-touroku address is where you're really supposed to be living at. Official postal mails such as voting cards are sent to this address, and you can only vote for candidates qualified for that area. But, for example, a young college student would typically keep his/her juumin-touroku at the home he/she used to live with his/her parents while living near a college far away. To vote, he/she can come home to his/her parents. Similar things are possible. For example, a whole family might move to another place while keeping the old juumin-touroku registered to the old house, so that they would have benefits of the old neighborhood.

In any case, one cannot legally live in an address that is registered under another person's valid juumin-touroku, unless they have obtained permission from that person. For this reason, many empty houses are being abandoned due to the original owner being suddenly deceased, aged enough to lose judgement, or disappeared for one sad reason or another. And this empty-housing situation has become a big problem in the society.

In other words, it is hard to believe that your daughter-in-law's family has a valid juumin-touroku, and the people living there now has no way to track that family.

The other thing is that I don't understand where the phone number comes from. A phone number is nothing official. You can contact your favorite phone company in Japan any time and change your number, and that information will not go to the offices that keep your koseki or your juumin-touroku. So just because you phoned a number that belongs to someone, that doesn't mean that the phone will be answered at a place that ever belonged to that someone.

Possibilities: Maybe what the cousin found was just a valid koseki and not the juumin-touroku. Or maybe the who answered the phone didn't know how real-estate matters worked. Or maybe that person hesitated to be open about personal information and simply made an excuse by saying he/she knows nothing. As for the phone number, there are too many possibilities on what's going on.

Either way, there is not much a "cousin" can do. If your daughter, who is the person on the same koseki, contacts the office in charge of that particular koseki, than the office may be able to give her more information on what she can do.

please do not mix up the two addresses, koseki address and (current) residential address. those are independent.

Wow thats a lot of information to go through.

The phone number was looked up some how and was not anything official, separate from the documents. The cousin said a phone was listed for the home address under some name, which she didn't tell me. But she said a person with a different name answered it. They said the (lastname) had moved away a long time ago. We are speculating that either one or both of the sisters could be living there with the parents.

The cousin sent my daughter in law a power of attorney to apply for the Koseki. I figured it was best she handled it because she could sneak in any extra questions, which is what I suspect happened.

Thank you very much for the information.