Overview
A major revision to the Japanese Civil Code, allowing parents to have joint custody after divorce, will take effect in April 2026.
Since this change represents a significant shift in Japan’s family law system, many people – including foreign residents in Japan – have raised questions about how it will work in practice.
While some practical aspects remain uncertain, this article explains the key features of the new system and how it differs from the current law.
Current Law – Only One Parent Has “Parental Authority” After Divorce
One distinctive feature of Japanese family law is that only one parent can hold parental authority (“shinken”) following a divorce.
When parents divorce by filing a divorce paper with the local city office, they must designate which parent will have parental authority for each child. The same requirement applies when they divorce through court mediation or litigation.
The parent with parental authority has the legal right and responsibility to manage the child’s assets, make important decisions concerning the child’s care, education, residence, and medical treatment, and consent to adoption if the child is under 15.
This parent also bears the obligation to care for and raise the child in the child’s best interests.
New Law – “Joint Parental Authority” After Divorce Will Be an Option
Outline
Under the new law taking effect in April 2026, parents will be able to choose to have joint parental authority after divorce.
The available options will be:
- Both parents have parental authority (joint parental authority);
- Only the father has parental authority; or
- Only the mother has parental authority.
If both parents agree on one of these options, their agreement will generally be respected.
When Parents Cannot Agree
If the parents cannot agree, they may attempt to resolve the issue through family court mediation. Mediators will assist them in finding a mutually acceptable solution.
If no agreement is reached, the Family Court will make the decision based on the best interests of the child, considering factors such as:
- the child’s relationship with each parent;
- the relationship between the parents; and
- all other relevant circumstances
(new Civil Code, Article 819(7)).
When the Court Must Grant Sole Parental Authority
Even under the new system, the court must award sole parental authority if joint parental authority would harm the child’s welfare. This includes situations where:
- a parent poses a physical or mental risk to the child; or
- joint decision – making is impracticable due to violence or other harmful behavior by one parent toward the other, or due to other relevant circumstances.
What Joint Parental Authority Means in Practice
General Rule – Parents Make Decisions Jointly
When parents have joint parental authority, the basic rule is that they make important decisions together — for example, decisions regarding:
- where the child will live,
- school selection,
- significant medical treatment.
It is important to note that joint parental authority does not require the child to spend equal time with each parent. Parenting schedules will be determined through a parenting plan, such as the child living with the mother from Monday to Thursday and with the father from Friday to Sunday.
When One Parent May Decide Unilaterally
A parent may exercise parental authority alone in the following situations:
- when the other parent is unable to exercise parental authority;
- when an urgent decision is required to protect the child’s interests;
- when the matter concerns day-to-day care and education.
(Article 824-2 (1)(2))
For example, if a school enrollment deadline is approaching and immediate payment is required, one parent may act alone to meet the deadline.
When Parents Cannot Agree on a Joint Decision
If parents disagree on an important matter that requires joint decision – making (e.g., choosing between public or private school), either parent may petition the Family Court. The court may designate one parent to make that specific decision.
(Article 824-2 (3))
Because court procedures take time, parents should file early when a decision has a firm deadline.
Special Rule Regarding Adoption
In Japan, adoption by a new spouse (e.g., a mother’s remarriage partner) is relatively common.
- If one parent has sole parental authority, that parent can consent to adoption for a child under 15.
- Under joint parental authority, both parents must consent.
If the parents disagree, a parent may petition the court to be designated as the parent who can make the decision unilaterally regarding adoption.
(Article 824-2 (3))
However, the court will make such a designation only when it is “especially necessary” for the child’s best interests. (Article 797 (4))
This higher threshold exists because adoption would terminate the biological parent’s parental authority, significantly affecting the parent – child relationship.
Designation of a Custodial Parent
The new law also allows the Family Court to designate a custodial parent – the parent with whom the child resides and who has broad authority over the child’s care, upbringing, and daily life, including decisions about residence (Article 824-3).
If a custodial parent is designated, the other parent – even one who shares joint parental authority – may not interfere with decisions concerning the child’s care, upbringing, or residence.
However, the extent to which this designation will affect other areas of parental decision-making has not been clearly defined under the new law. It also remains unclear how frequently courts will make such designations in practice. The scope and practical use of this system will likely become clearer as court practice develops over time.
Changing a Previous Sole Parental Authority Decision
Parents who divorced before the new law came into effect – and designated one parent as the parental authority holder – may apply to change to joint parental authority.
The court will decide based on whether the change is in the child’s best interests, taking into account:
- the circumstances of the original agreement (including whether there was domestic violence, whether mediation was used, or whether a notarial deed was executed);
- how circumstances have changed since then; and
- other relevant factors
(Article 819 (8)).
The Ministry of Justice Q&A also notes that the court may consider how each parent has fulfilled parental responsibilities – such as paying child support – and whether they have respected each other’s dignity and cooperated in raising the child.
Inquiries and Legal Assistance
This article provides a general explanation of the joint parental authority system starting in April 2026. Some practical details remain uncertain and will depend on future court practice.
The contents of this article do not constitute legal advice.
If you would like individualized consultation or legal assistance regarding your case, please feel free to contact me through the contact form.
