How to legally recognize a baby born out of wedlock in Japan (incomplete article)

What is affiliation of a child?

Ninchi-todoke “認知届け”is literally means recognition report in English and its official English name is “Affiliation of a child”. Ninchi “認知” = affiliation is a concept that accepts parent-child relationship legally about a child born between unmarried couple.

Ninchi action is roughly divided into two types which are voluntary affiliation and compulsory affiliation.

When a father recognizes a newborn baby as his child, legal parent-child relationship is accepted from the day when a child was born and a variety of rights and obligations involved with a child is generated.

A father need to not only pay expense of bringing up a child but also a child is legally added to a legal heir of a father.

Parental authority basically belongs to a mother even after affiliation of a child is accepted but it is possible for a father to have parental authority if “notification of parental authority management ” after a father and a mother discuss sufficiently.

Voluntary affiliation

Voluntary affiliation is that a father recognize a baby as his child who is born or unborn between an unmarried father and a mother.

You need to submit affiliation report to a municipal office located where either a born child’s permanent domicile by birth or father’s. If affiliated baby is an unborn child, it is sometimes called “affiliation of unborn child”.

Voluntary affiliation is done by a father’s voluntary and basically there is no need to get a mother’s consent and child’s consent. However, if a child is already an adult, a father needs to get a child’s consent.

Compulsory affiliation

This is a legal manner that forces a father who doesn’t recognize a baby as his child born between unmarried father and mother to accept that a baby is his child.

A child or a mother files an arbitration and a trial to a family court. “Affiliation arbitration petition” needs to be submitted to a family court which is located around where a father lives.

However, a mother and a child can’t file for a trial from the beginning. First thing first, a mother and a child need to file for an arbitration to a family court. The timing a mother file for a trial is when a father responds to this arbitration.

Factual principle and filiation principle

Factual principle

Regarding parent-child relationship of a child born between unmarried couple, mother-child relationship is naturally generated by the fact of childbirth so Japanese law takes in factual principle(Jus snguinis) that accepts automatically mother-child relationship at the time biological child-parent relationship is recognized.

Filiation principle

Father-child relationship is established by an affiliation procedure. Filiation principle that accepts chid-parent relationship by a father’s legal indication that a baby is his child is adopted in this case. Even if there is biological relationship between father and a child, unless reporting the affiliation to municipality, a father and a child are not accepted as legal parent-child relationship.

Requirements of affiliation of a child

So many countries including Japan adopts this affiliation principle but it is not that anybody can get legal acceptance of child-parent relationship but affiliation system is to establish parent-child relationship by father’s acceptance of its biological relationship with a child born between unmarried couple so generally, affiliation by a person who has no biological relationship with a child is not accepted.

However, the supreme court takes its stance that every cases needs to be applied to Article 772 of Civil Law Act

• “A child conceived by a wife during marriage shall be presumed to be a child of her husband”




• “A child born after 200 days from the formation of marriage or with in 300 days of the day of the dissolution or rescission of marriage stage resumed to have been conceived during marriage.”

it is possible to meet the case that legal parent-child relationship is different from biological parent-child relationship.

Requirements of establishment of child-parent relationship

International law has the following criteria about a parent-child relationship between an unmarried father and a mother, and a child

• Parent-child relationship between a father and a child at the time when a child is born is in accordance with father’s national law.
• Parent-child relationship between a mother and a child at the time when a child is born is in accordance with mother’s national law.

However, If there is a regulation in the national law like “Getting agreement and acceptance from a third-party at the moment parent-affiliation is recognized by child’s parents on establishment of its relationship is a requirement of affiliation”, you need to satisfy the requirement, too.

This is because of avoiding the situation that a father recognize a baby as his child in purpose of expecting a child to support his life when a child grows up. These regulations are all for protecting child’s life.

Requirements of establishment of child-parent relationship in Japan

The substantial requirements of “voluntary affiliation” that a father recognize a child voluntarily is the following. Affiliation is established by submitting a family register certificate to a municipality.

Requirements of father

• A person who recognize a child needs to be a biological father.
• A person who recognize a child needs to have an intention to accepting a child

Requirements of child

• A child need to be the one born out of wedlock, who is yet affiliated by nobody
• If an affiliated child is over 20, a father needs to have child’s consent
• If affiliating a dead child, a child must have lineal descendant.
• If affiliating unborn baby, a father needs to have child’s mother’s consent.

How to carry out the procedure of affiliation of a child

Case 1: Affiliation of a child born between an unmarried non-Japanese father and an unmarried Japanese mother

If legal principle of a father’s country is “factual principle”

A child’s nationality is provisionally Japanese and a mother will have to have the birth registered to a municipality. A child enters mother’s family register and a child’s family name becomes mother’s one.

To list non-Japanese father’s name on newborn baby’s family register, a father’s name needs to be filled in a column of father
in registration of birth report and a father also needs to prepare

• A certificate of nationality(passport)
• a certificate that shows a father’s country adopts factual principle
• certificate documents that prove a father. ( a statement that a father declares a baby is his child with his signature, a certificate of registration of a birth)

Then, father’s date of birth is reflected with child’s birth registered date and a baby’s date of birth on child’s family register.

By the way, if a mother and a father get married each other, a child becomes a legitimate child from illegitimate one. This is according to Clause1, article 30, Act on General Rules on marriage legitimation,

A child shall acquire the status of a child born in wedlock if the child is legitimated under the national law of the father or the mother or of the child at the time when the facts constituting the requirements for legitimation are completed.

Case 2: Affiliation of a child born between an unmarried Japanese father and an unmarried non-Japanese mother

In case a Japanese father recognize a child, if satisfying Japanese affiliate principle requirements, a Japanese father needs to submit affiliation report to a municipality.

However, child’s protection requirements need to be satisfied. For example, if a mother is Korean, child’s nationality is Korean because Korea’s law principle of child recognition is factual principle(biological principle) and legal certificate that regulates child’s protection requirements on affiliation and a certificate that prove a child has protection requirements needs to be submitted to a municipality.

Case 3: Affiliation of a child born between an unmarried non-Japanese father and an unmarried non-Japanese mother

If legal principle of a father’s country is “factual principle”

Regarding a child born out of wedlock between unmarried non-Japanese mother and unmarried non-Japanese father from the country that adopts factual principle, parent-child relationship between a father and a child is naturally established even without recognition from a father.

What parents do in Japan is just to report that a child enter mother’s family register in their country to municipality.

What parents need to report to a municipal office is

• Subsequent completion report of family register
• Certificate of birth registration of a child
• statement that a father declares a baby is his child with his signature
• Passport