Every Child

Has Two Parents


Overview of the koseki Family Registration System


The koseki is often confused with the jyuminhyou.  The jyuminhyou registers your current address, and is not the same document as the koseki.  Follow the links for more information.

The koseki, or Family Registration, is the system by which births, deaths, marriages and divorces of Japanese nationals are recorded.  In some sense, it is a national identity registration, since Japanese public offices collect and maintain these detailed records about all Japanese citizens. Under Family Registration Law, foreign nationals living in Japan also have to notify a municipal office of the births and deaths of their family members. When they marry, divorce, or have children, Japanese nationals, must notify a municipal office. All this and more are recorded in the koseki.  A person's koseki follows them for their entire life. 

The format of a koseki has changed over the years.  It used to be hand written, but is now, of course, printed on a computer, and then stamped with a hanko to verify authenticity.  Once issued, it is good for 3 months.  (Or was it six months?  It says so on the copy you get.) 

Each koseki has a "head" of the family unit, listed at the far right, as well as a honseki-chi, the owner's symbolic home.  (Described in more detail later on.)  You must know both of these in order to get a copy of a koseki, although there are other ways to find these if you have a legal right to, as described below.  A koseki is held at the municipal offices in the town, city, or village for that honseki-chi.

In the event that an individual on a koseki of which they are not the "head" of, marries and creates a new family unit, a note is made in their new koseki which states the name and honseki-chi of the koseki from which they seceded.  (When Japanese marry foreigners they form  their own koseki. Women can also have their own koseki in the case of muko-yoshi, when a man is "adopted" by the family of the his wife.) You'll likely find that both forms of records contain a wealth of information. Koseki family registries however are held with a deference similar to that with which adoption records are held in some other countries; their contents are considered extremely private.  Unlike the jyuminhyou, a koseki is not commonly used to verify information, and is not normally required to get government services.  Since the koseki provides information mostly on family relationships, it has historically been used for discriminatory purposes, and many private investigators and others seem to have ways to get copies when they should not legally be able to.

Normally, everyone on a koseki must have the same last name.  Of course, many Japanese, particularly women, object to this.  When a non-Japanese marries a Japanese, the non-Japanese is listed as the spouse, but the head of household must remain the Japanese partner, regardless of gender.  As of at least 2005, upon marriage, both the foreign spouse and the Japanese spouse will be given the opportunity to change their last name to that of the other. (Reported true for a foreign man and Japanese woman and assumed true for the reverse, although this has not been confirmed.)  Reportedly, this is also still possible for 6 months, but after that may require extra paperwork and expense.

A child is listed on his or her parent's koseki until they create their own.  This typically happens when they get married.  But in case of a divorce, the child will move to the person with shinken (legal custody.)  In case of a non-Japanese getting full custody in Japan, you should break your child off of the Japanese parent's Family Registration and onto his or her own.  (You probably need both Shinken and Kangoken types of child custody.) This is not a complete solution to a future abduction by the Japanese parent, but it will make it more difficult, since it will be clearly obvious that the Japanese parent does not have custody.  It will take an additional legal procedure to move the child back.  So it is one more obstacle and a good precautionary and preventative measure.

Records of civil actions pertaining to non-Japanese citizens, such as marriage, adoption, divorce or death are available from the Municipal Office where the action was registered, in the same manner as the birth record of a non-Japanese citizen.  Marriage and adoption records are maintained for 50 years.  Divorce and death records are kept for 10 years.

Related Terms

Hittousya 筆頭者 【ひっとうしゃ】

The head of the family, listed on the far right of the koseki.

Honseki-chi 本籍地 【ほんせきち】

This is often just referred to as the "honseki".  This is the place where one is registered. Dictionaries define this as the "domicile" however indviduals may live in one town and retain their koseki in a different village. It may better to think of this as the place one considers their true home, new home, real home, birth place, or an important place in their family's or genealogical past.  The honseki is literally, an address. The address itself seems to usually slightly shorter than a real address you might live at, leaving out the final "ban" part.  But that address determines what government office controls the koseki. So that is who you send any koseki related requests, notifications, etc to.

Depending upon the individual's preference, they may transfer their family registry or koseki to the city they live in and this new town would become their new "home place" or honseki-chi. Family abstracts, koseki shouhon, and entire family records, koseki touhon, therefore may list previous towns, villages, or cities in which the family registry was held; basically a list of places that previously may have been considered home (or the honseki-chi) by the individual. An owner can move their honseki at will.  But if you know it once, you can fill out more forms to track where it has moved to.  A hassle, but should be doable.  (Although I believe it is worth the money to pay a lawyer to do this, since it may involve multiple forms, submissions and waiting time in between.)

People often times leave their birth place but still consider it their "real" home. Though some individuals move to a large city or completely different prefecture than that in which they were born, they may choose to maintain their koseki in their hometown or place of birth. The city, village, or town where an individual chooses to maintain their koseki (family records) is called the honseki-chi. The possibility therefore exists that an individual could reside for the majority of their life in a big city (for example Tokyo), but could choose to maintain their family registry in the place they consider their home, their honseki-chi (for example Nagoya). On the other hand, the honseki may not in fact be a real location that a person might live at.  For example, some people are rumored to use the Imperial Palace for their Honseki.

Koseki Touhon 戸籍謄本 【こせきとうほん】vs. Koseki Shouhon 戸籍抄本 【こせきしょうほん】

  1. Koseki Touhon - Alternate romanization: tohon, touhon.

  2. Koseki Shouhon - Alternate romanization: shohon, shouhon, syouhon.

There is really only one family registry for each family but the contents of the registry are available in two styles or formats. They are referred to in Japanese as koseki touhon and koseki shouhonTouhon in koseki touhon means a copy, a transcript, or a duplicate. A koseki touhon therefore refers to one's entire family registry which would include the names of relations beyond one's own parents. Shouhon in koseki shouhon refers to an abstract, an extract, or an excerpt.

As implied, the koseki shouhon is merely a swatch or a piece of one's family register. A koseki shouhon will likely only list a specific individual's name along with the names of his or her parents, the specified individual's date of birth, their birth order number or title in respect to gender, and the specified individual's place of birth which may or may not include the name of the prefecture, the name of the county or district, and the name of the city, town, or village. The shouhon also usually notes who brought forth or informed the municipal office of specific information and the date that the information was received by the office.

The koseki shohon usually omits outdated records such as annulled adoptions, former marriages, divorces or deaths of former spouses. In case of a person who was removed from one koseki and placed into another by adoption or marriage, the current koseki sometimes does not indicate place of birth. If the omitted portion is required, you will need to get an extract from the canceled koseki (joseki shohon) from the Municipal Office holding the applicant's previous family register.  (It may not be necessary to actually go to that office.  Ask at your local office to see if they can get it for you.)

If you request a koseki from a government office, always request the koseki touhon.  They will probably give it to you.  Worst case you will get the shouhon.  But request the touhon.

Koseki Fuhyou 附票 【ふひょう】

alternate romanization: none.

Jyouseki touhon 除籍謄本【じょせきとうほん】

Alternate romanization: joseki tohon

A canceled koseki, i.e. one from a person's previous family register.  There is a special form to fill out to get these if some information you want is missing on the koseki touhon.

Kaiseigen koseki 改製原戸籍【かいせいげんこせき】

alternate romanization: none.


Transferring to a new home place. When one finally decides to break with their old home town and transfer their family registry to their new town of residence, a note is made on the koseki of this transfer. This note is called tenseki and states from where to where, by whom, and when the honseki-chi was changed or transferred.

Who can get a copy of a koseki

Koseki records are not held library style where one may gain access to the records by simply entering the appropriate room. They are held and protected by the city hall of the honseki-chi, so only city employees are allowed access to these records. Additionally, there are laws about who can get a copy of whose koseki.  But basically, if you are listed on it, you can always get a copy.  This is why you want to register your marriage and your children.  Once listed as a spouse or parent, your name will never go away.  So in this case,  the government official can just look at the koseki itself and see your name on it, and see the name on your ID (foreigner registration or passport).  Since they match, they will give you a copy, no problem. It is self-identifying.  Therefore it is also highly likely that you could get one for an ex-wife even if there were no children, for example, since the divorced spouse's name is merely crossed off, not erased. You could just say that you need it for evidence of the divorce. For a child born out of wedlock, the foreign parent's name is there also, so no problem.

How to get a copy of a koseki

The first step is that you must find the name of the local government office that corresponds to the honseki-chi. If you already have a copy of the koseki, it is listed prominently.  It is also listed on a Residency Registration (jyuminhyou) document, and may possibly be listed on other legal documents.  Look over anything that you have.  In any case, once you know the honseki-chi, our section on how to find the location of the Japanese local government office will help find the corresponding office.  If you do not already have the honseki-chi, things get more difficult.

The easiest way to get a koseki or honseki-chi for the first time, is to contact a lawyer and pay them to get it for you.  They have special privileges for searching and acquiring legal documents like the koseki and Residency Registration (jyuminhyou).  This is not cheap and will probably cost in the neighborhood of 20-30,000 yen. (Making use of a What is a  gyoseishoshi lawyer rather than a full bengoshi lawyer may save you some money.  But using a lawyer is usually worth it in terms of the time, effort and expense it would cost you to try to do this alone. Doing it alone would certainly require one or more in-person visits to local government offices in Japan.  (It may be possible to get help from a Japanese embassy, but I have never heard of anyone successfully doing this.)  The only exception might be if you know the exact previous address of where the person once lived.  If you can get to the corresponding local government office and can clearly prove your legal right to the information, they might look up the honseki-chi from the previous Residency Registration (jyuminhyou) for you.  But be prepared to clearly prove that you deserve the information, and understand that their idea of "clear" may not be the same as yours.  If you believe you have the right, ask how to submit a request to the Mayor (the xxx-chou of that governmental division) who has the final right to approve or deny your request.  This extra paperwork might encourage them to cooperate. 

Lawyers would need some kind of personal information to start with, such as a previous addresses.  They might also be able to work from more general information such as the city, the name of a workplace, birthplace, parent's residence address, etc.  But the more vague your information, the more it is likely to cost.  In any case, lawyers are usually very careful that whoever they do this for actually has the legal right to get it.  If you are listed on the koseki, for any reason, there should be no problem.  If you claim to be listed but turn out not to be, then the lawyer will not likely give you a copy, even if you have already paid them.  If you are not listed, but need to initiate a legal procedure against someone on the koseki, or need to submit a legal form concerning information listed on a koseki, then you may still have a legal right to find the honseki-chi and or get a copy of the koseki.  The following list contains some possibilities:

  1. A mother who needs to initiate a paternity suit.

  2. A mother may need to sue for child support.

  3. A father may need to submit a nichi todoke (request for recognition of paternity)

  4. A father may need to initiate a lawsuit for dissolution of the paternal relationship of another man who is not actually the father.  (Requires koseki of that man.)

  5. A husband or wife who wants to register an overseas marriage that the Japanese spouse has not registered yet.

  6. A mother or father who wants to register a child's birth (with them as the parent) which the Japanese spouse has not registered yet.

  7. If you know any others, please let us know so we can include them here.

In these cases, the lawyer will need to get a copy of the koseki, and might give you a copy also.  You should confirm in advance though that you can get a copy before paying any money.  Even if the lawyer him or herself will not be the one to handle the lawsuit or other proceeding that requires the koseki or honseki-chi, a less diligent lawyer may be persuaded to give you a copy in exchange for a higher than normal payment.  Or they may just give you the name of the head of the household and the honseki-chi, which is exactly all you need to file the various papers at the local government office.  (Im not sure of the legal restrictions on just giving out the honseki-chi.  It is possible that this is not so strict as it then transfer the final responsibility to the local government office.)  For some layers, like those you can contact easily from the various low cost legal consultation services this may be seen as an easy way to make some extra money, since in most cases it involves little work and low cost.  They just have the office staff fill in a form and submit it.  In some cases, you may actually need the koseki yourself, for example to submit the ninchi todoke or register a marriage or birth, which is usually done in person at the local government office.  Even if you had to pay the lawyer to do this initial paperwork (which you could otherwise do yourself) it is worth it, because you are then listed on the koseki and have a legal right to get a copy at any time in the future.

Once you have the honseki-chi or an actual copy of the koseki (which lists the honseki-chi on it) the easiest thing to do is to go there and request a copy in person.  Another option is to request one by mail.

Procuring Your Family Registry in Person

The easiest way is to collect a copy of your records by applying in person.  If you show up at the local government office, be prepared to prove your relationship and ties to the individual whose koseki you are seeking.  Fill out the appropriate forms with an appropriate reason for wanting the registry, and pay the applicable fee.  You should have no problem getting an official copy.  They will help you with the forms if you need help. You can also get a copy of the form to do this and further information on how to do this on our Japanese Family Law Related Forms section. 

If the government office is far away, you can also go to your own local government office and fill in forms there.  These can be submitted (not sure if by mail or to people in the office you are at) and will be forwarded to the appropriate office of the honseki-chi.

Procuring Your Family Registry by Mail

You may try to request a copy of your family registry by mail. You will be required to state clearly in your letter of request why you wish to have the registry and what your relationship is to the individual whose registry you are seeking. You can get a copy of the form to do this and further information on how to do this on our Japanese Family Law Related Forms section.  The koseki fee is generally about ¥500 per copy, but note that you must also include postage along with the koseki copy fee.

Koseki Related Laws and Regulations

See our Japanese Family Law section.

Because of the wealth of information contained in the family registries, the municipal offices of all cities, towns, and villages regard these records as extremely private in nature. The Koseki regulation referred to as Hourei prescribes the information which koseki records will contain as well as the occasions on which municipal offices must be notified of changes within the family so that the record can be appropriately updated. The Koseki regulation can be viewed in Japanese here. Section 10 of the hourei regulation states who may obtain records.  The governing body of the respective village, town, or city may refuse the request if they deem your reason for wanting a copy of the koseki as inappropriate. The mayor of the village, city, or town is the first and has the final authority over which reasons are considered appropriate. The city employees in their responses to requests for copies of koseki follow guidelines established by this higher governing authority.


What no-one ever told you about a koseki.  If you read Japanese, a very good reference on the koseki. (cached copy)

The information on this website concerns a matter of public interest, and is provided for educational and informational purposes only in order to raise public awareness of issues concerning left-behind parents. Unless otherwise indicated, the writers and translators of this website are not lawyers nor professional translators, so be sure to confirm anything important with your own lawyer.

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