While a koseki's format may vary depending the prefecture and year it was established, these examples will hopefully provide a general overview of their layout. The kanji characters appearing in the title blocks on these forms are read from right to left or from top to bottom. The example we have provided is a blank form listing only the title sections. Notes generally appear below the title sections.
A Honseki, the address where the person is registered or maintains their koseki
In the examples I have the prefecture is listed first followed by the district/county, the village name, and finally the specific house address.
BZenkoshu, the previous head of the family
This title no longer appears on the newer koseki. (This was possibly a change made after World War II.) As it says, the name which appears here was the previous head of the family.
C This section is the place where various dates and events are noted about the family. This section hosts two types of information, basically information about those coming into the family and information about those who leave the family. (If you have been denied access to your koseki touhon, it is possibly because of the names of various people noted in this section.) Appearing in this section are notes referred to as nyuuseki which state who was added to the koseki, when, and also for what reason. (For example births, marriages, adoptions.) Joseki notes are just the opposite of nyuuseki notes. They are notes which indicate who, when, and why someone was removed from the koseki. (For example deaths and divorce.)
D Zenkoshu tono Tsudukigara, states the relationship between the individual that the koseki is about (named in section H) and the person named as the previous head of the family (named in section B). This section also seems to be excluded from newer koseki layouts.
E Chichi, the father of the individual whom the koseki is about (individual named in section H)
F Haha, the mother of the individual whom the koseki is about (individual named in section H)
G The birth order of the individual whom the koseki is about (individual named in section H) according to gender. The first born boy of a Japanese family is referred to as chounan. The second son born to the family is referred to as jinan. The third born son is referred to as sannan. The first daughter born to the family is referred to as choujo. The second daughter is referred to as jijo. The third daughter is referred to as sanjo. There are further birth order names according to gender (I'm told they're infinite), however there is a limit to the information we can offer on this page at this time. If you have a question about a birth order name according to gender, drop us a message and we'll try to field your question.
H The individual to whom all this information relates.The main person.
I Shussei, the individual's (individual named in section H) birth date. Years appearing in this section are based on the Japanese nengou or emperor year system.