Koseki Family Registry in Japan

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Kosek Family Registry

Koseki family registry is an official document that registers every Japanese citizen, and it plays a role of all birth, death, marriage and divorce certificates. Please note it doesn’t register non-Japanese citizens. 

In order to obtain the record, you must provide following information to the city hall where the Koseki record is registered to:

  • Honseki (Permanent domicile)
  • Head of family in Japanese writing.

Koseki Registry Sample

Juminhyo Residence Registry

There is another system: Juminhyo Residence Registry which is different from Koseki family registry. The Juminhyo residence register records your current address. 

Certificate of Acceptance of Vital Records

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. 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.


Family Tree
Koseki registry

All About Koseki Registry

The format of a Koseki has changed over the years. It used to be hand-written, but is now printed on a computer, and then stamped with a stamp (Inkan/Hanko) to verify authenticity.

Each Koseki has a “head” of the family unit as well as a Honseki-chi, the owner’s symbolic home. 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 where Honseki is located. 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 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 where a husband is “adopted” by the family of his wife.) You’ll likely find that both forms of records contain a wealth of information.

Koseki family registries, however, are held with deference similar to that with which adoption records are held in some other countries; their contents are considered extremely private.

Normally, everyone on a Koseki must have the same last name. When a non-Japanese marries a Japanese, the non-Japanese is listed as the spouse, but the head of family must remain the Japanese partner, regardless of gender. Upon marriage, both the foreign spouse and the Japanese spouse can change their last name to that of the other.

A child is listed on his or her parent’s Hoseki 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 child custody.

Honseki or the permanent domicile

Honseki is the place where one is registered. Dictionaries define this as the “domicile” however individuals 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, a real home, birthplace, 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 records to the city they live in and this new town would become their new “home place” or Honseki. Koseki records, 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) by the individual. An owner can move their Honseki at will. You can theoretically trace all the Koseki records one by one, but it involves multiple forms, submissions, processing fees and waiting time in between. You can never obtain them online. 

People oftentimes leave their birthplace 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. 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 (for example Kyoto). 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.

We have a wealth of experience in dealing with businesses such as real-estate agencies, company creditors, financial institutions and insurance companies who need to locate individuals in Japan for legal purposes.

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