What if an heir has dementia, is missing, or is a minor? Choosing between adult guardianship, an administrator for an absentee and a special representative

In short: estate division discussion is a procedure in which the co-heirs are the parties. If an heir lacks sufficient mental capacity, is missing or is a minor, the discussion cannot proceed while that person is left out, and the parties' side has to be arranged through a Family Court procedure first. For a person whose capacity is insufficient, commencement of guardianship, curatorship or assistance may be considered (Civil Code 民法, Articles 7, 11 and 15); for a missing person, appointment of an administrator of the absentee's property (Civil Code, Article 25, paragraph 1) or an adjudication of disappearance (Civil Code, Article 30); and where a minor and the person with parental authority are both heirs, appointment of a special representative (Civil Code, Article 826, paragraph 1). Yotsuba Administrative Scrivener Office collects family registers, investigates heirs, organises the inheritance relationship and estate materials, prepares the documents used for the application for a certified list of statutory heirs, and prepares estate division agreements once agreement is reached. Preparation of documents to be filed with the Family Court is a judicial scrivener or attorney, and judgement and agency in disputed cases is an attorney.

Why does the estate division discussion stop?

Co-heirs may at any time divide all or part of the estate by their discussion, apart from exceptions such as prohibition by will (Civil Code, Article 907, paragraph 1). Conversely, the discussion is a procedure in which the co-heirs are the parties, and every person who is a party must take part.

If an heir cannot decide and sign or seal for themselves, cannot be contacted, or is a minor who cannot validly take part alone, that premise is not met. Proceeding "with the remaining heirs for now" is not an available route.

For fixing who the heirs are, see Where does an inheritance start? and The basics of statutory heirs and shares in inheritance. This article begins only after the heirs have been fixed.

A case where opinions conflict and agreement cannot be reached is a different matter, belonging to Family Court conciliation and adjudication. See What to do when heirs cannot agree.

What is used when an heir's mental capacity is insufficient?

The Civil Code sets out three categories according to the degree of capacity affected by a mental disorder. Each begins with an adjudication of the Family Court.

Category	Provision	Statutory requirement
Commencement of guardianship	Civil Code, Article 7	A person who constantly lacks the capacity to appreciate their situation
Commencement of curatorship	Civil Code, Article 11	A person whose capacity to appreciate their situation is extremely insufficient
Commencement of assistance	Civil Code, Article 15	A person whose capacity to appreciate their situation is insufficient

A petition for commencement of guardianship may be filed by the person, the spouse, a relative within the fourth degree, a guardian of a minor, a supervisor of a guardian of a minor, a curator, a supervisor of a curator, an assistant, a supervisor of an assistant or a public prosecutor (Civil Code, Article 7). The petition is filed with the Family Court having jurisdiction over the person's address.

Who is appointed as adult guardian is decided by the Family Court. A candidate may be proposed with the petition, but the candidate is not necessarily appointed.

An adjudication of commencement of guardianship is rescinded when the cause has ceased to exist (Civil Code, Article 10). It is not a system that ends automatically once the estate division is over. Confirm this point with the Family Court, an attorney or a judicial scrivener before filing.

What if the adult guardian is also an heir?

Where the adult guardian and the adult ward are both heirs, an estate division discussion may amount to an act in which the interests of the two conflict.

Civil Code Article 860 applies Article 826 mutatis mutandis to a guardian in respect of acts involving a conflict of interest, except where there is a supervisor of the guardian. Where there is a supervisor of the guardian, the supervisor represents the ward (Civil Code, Article 851, item 4).

Where there is no supervisor, a petition for appointment of a special representative is filed with the Family Court that made the adjudication of commencement of guardianship. The filing fee is revenue stamps of 800 yen, and a draft estate division agreement is submitted as material concerning the conflict of interest (Courts, "Appointment of a special representative (temporary curator or temporary assistant) concerning an adult ward, person under curatorship or person under assistance", accessed 22 August 2026).

In other words, the draft agreement is needed before the appointment. Preparing the draft falls within the scope our office handles.

What if an heir is a minor?

A person reaches the age of majority at 18 (Civil Code, Article 4). Where an heir is under 18, as to an act in which the interests of the father or mother exercising parental authority and the child conflict, the person exercising parental authority must request the Family Court to appoint a special representative for the child (Civil Code, Article 826, paragraph 1).

An estate division discussion where the person with parental authority is also an heir of the same deceased is given in the courts' procedural guidance as a typical example of such an act (accessed 22 August 2026).

Where a person exercising parental authority does so for several children and the interests of one child conflict with those of another, the appointment of a special representative for one of them must be requested (Civil Code, Article 826, paragraph 2). Where there are several minor children, appointments may be needed according to the number of children.

Item	Content
Basis	Civil Code, Article 826, paragraphs 1 and 2
Who may file	The person with parental authority, an interested party
Where to file	The Family Court having jurisdiction over the child's address
Filing fee	Revenue stamps of 800 yen per child
Postage	Differs by court
Main attachments	Family register of the minor, family register of the person with parental authority, certificate of residence or family register attachment of the proposed special representative, material concerning the conflict of interest such as a draft estate division agreement

Here too, the draft estate division agreement is needed first. Whether the content is disadvantageous to the minor is examined by the Family Court. Our office does not guarantee the outcome of that examination.

What if an heir is missing?

Where a person who has left their former domicile or residence has not appointed an administrator of their property, the Family Court may, at the request of an interested party or a public prosecutor, order necessary measures for the administration of that property (Civil Code, Article 25, paragraph 1). This is the appointment of an administrator of an absentee's property.

For the appointed administrator to take part in an estate division, permission of the Family Court for an act exceeding authority is required. Civil Code Article 28 provides that where an administrator needs to perform an act exceeding the authority prescribed in Article 103, the administrator may do so with the permission of the Family Court. The courts' procedural guidance likewise explains that the administrator "obtains the Family Court's permission for an act exceeding authority and then carries out estate division, sale of real estate and so on for the absentee" (accessed 22 August 2026).

Item	Content
Basis	Civil Code, Article 25, paragraph 1, and Article 28
Who may file	An interested party (spouse, heir, creditor and the like), a public prosecutor
Where to file	The Family Court having jurisdiction over the absentee's former domicile or residence
Filing fee	Revenue stamps of 800 yen
Postage	Differs by court
Advance deposit	May be required where the property is expected to be insufficient for administration
Main attachments	Family register and family register attachment of the absentee, certificate of residence of the proposed administrator, material evidencing the absence, material on the property, material evidencing the interest

The amount of the advance deposit differs by case. To fix the amount in advance, confirm directly with the Family Court where the petition will be filed.

How is an adjudication of disappearance different?

An adjudication of disappearance deems an absentee to have died in law. Where an absentee's life or death has been unknown for seven years (ordinary disappearance), the Family Court may make the adjudication at the request of an interested party (Civil Code, Article 30, paragraph 1). For a person who was on a battlefield, was aboard a vessel that sank, or encountered another peril that could cause death, the adjudication may be made where their life or death has been unknown for one year after the peril ended (paragraph 2 of the same Article).

The starting point of the effect differs between the two. A person under ordinary disappearance is deemed to have died when the seven-year period expired, and a person under peril-based disappearance when the peril ended (Civil Code, Article 31). Who the heirs are changes according to that deemed point in time.

Comparison	Administrator of an absentee's property	Adjudication of disappearance
Position	The absentee is presumed alive and the property is administered	Deemed to have died in law
Period requirement	None	Seven years for ordinary disappearance, one year for peril-based disappearance
Participation in estate division	The administrator takes part with permission for an act exceeding authority	The absentee ceases to be an heir, depending on the deemed date of death
Filing fee	Revenue stamps of 800 yen	Revenue stamps of 800 yen
Official gazette publication fee	Not required	5,298 yen (3,359 yen for the demand for notification of disappearance plus 1,939 yen for the adjudication of disappearance)
Where to file	The Family Court having jurisdiction over the absentee's former domicile or residence	The Family Court having jurisdiction over the absentee's former domicile or residence

Which to choose depends on the prospects for life or death, the years elapsed and the content of the estate. Confirm the choice itself with an attorney.

What if it is unclear whether there are any heirs at all?

"There is a missing heir" and "it is not clear that there are heirs" are different situations. Civil Code Article 951 provides that where it is not clear that there are heirs, the inherited property constitutes a juridical person.

What is considered in that case is the appointment of an administrator for the liquidation of the inherited property. According to the courts' procedural guidance, the petition is filed with the Family Court having jurisdiction over the deceased's last address, the filing fee is revenue stamps of 800 yen, and in addition to contact postage an official gazette publication fee of 5,582 yen is paid after the Family Court so directs (accessed 22 August 2026).

There are also cases where renunciation of inheritance results in there being no heirs. On renunciation itself, see Before considering renunciation of inheritance or qualified acceptance.

How much does it cost?

The expenses paid to the Family Court are as follows. All are actual expenses, separate from a professional's fee. Contact postage differs by court, so confirm with the court where the petition will be filed.

Procedure	Filing fee	Other actual expenses
Commencement of guardianship (Civil Code, Article 7)	Revenue stamps of 800 yen	Registration fee in revenue stamps of 2,600 yen, postage, expert examination costs (which the petitioner may bear)
Appointment of a special representative (Civil Code, Article 826, paragraph 1)	Revenue stamps of 800 yen per child	Postage
Appointment of a special representative (conflict of interest between an adult ward and an adult guardian)	Revenue stamps of 800 yen	Postage
Appointment of an administrator of an absentee's property (Civil Code, Article 25, paragraph 1)	Revenue stamps of 800 yen	Postage, advance deposit where required
Adjudication of disappearance (Civil Code, Article 30)	Revenue stamps of 800 yen	Postage, official gazette publication fee of 5,298 yen
Appointment of an administrator for liquidation of inherited property (Civil Code, Article 951)	Revenue stamps of 800 yen	Postage, official gazette publication fee of 5,582 yen

The amounts above are those published in the courts' procedural guidance (accessed 22 August 2026). Expert examination costs and advance deposits vary by case. Because the time required for examination differs by case and by court, this article does not give an estimate of duration.

What happens to procedures that have deadlines?

Deadlines in the inheritance continue to run while the Family Court procedure is pending.

Deadline	Content
Three months	The period for acceptance or renunciation from the time the heir became aware that an inheritance had commenced for the heir (Civil Code, Article 915, paragraph 1). It may be extended by the Family Court at the request of an interested party or a public prosecutor
Four months	Final income tax return for the deceased
Ten months	Inheritance tax return and payment
Three years	Obligation to apply for inheritance registration

The starting point of each deadline differs by system. For details, see Summary of deadlines in inheritance procedures. On whether an inheritance tax return is required, see Is an inheritance tax return required?, and on registration, see How does inheritance registration proceed?.

While the discussion is stalled, the system covered in When can a deceased person's bank account be accessed? is relevant to immediate payments from deposits. For identifying the property, see Investigating the estate and preparing an inventory.

What can and cannot be asked of an administrative scrivener?

Yotsuba Administrative Scrivener Office collects family registers, investigates heirs, organises the inheritance relationship and estate materials, prepares the documents used for the application for a certified list of statutory heirs, and prepares estate division agreements and similar documents once agreement is reached. Preparing the draft estate division agreement that must be attached to a petition for appointment of a special representative or for permission for an act exceeding authority also falls within this scope.

Preparation of the petition and other documents to be filed with the Family Court itself is not handled. Nor does the office make the individual legal judgement of which procedure should be filed against whom.

• Preparation of documents to be filed with the Family Court → a judicial scrivener or attorney
• Choice of procedure, agency in the petition, disputed cases → an attorney
• Inheritance registration → the person concerned, or a judicial scrivener or attorney
• Inheritance tax returns and tax computation → the person concerned, or a tax accountant
• Sale appraisal and brokerage of inherited real estate → Yotsuba Real Estate Co., Ltd.

Yotsuba Administrative Scrivener Office and Yotsuba Real Estate Co., Ltd. respond as separate business entities under separate contracts. Our office receives no referral fee. For the sale or use of inherited real estate, see Consultation on inherited real estate.

How can a consultation proceed in Bunkyo Ward?

Yotsuba Administrative Scrivener Office (Kohinata, Bunkyo Ward; about five minutes on foot from Myogadani Station) guides collection of family registers, investigation of heirs, organisation of estate materials, matters relating to the certified list of statutory heirs and preparation of estate division agreements step by step. Where a Family Court procedure is needed, we explain the route of instructing a judicial scrivener or attorney directly.

For the flow of engagement see Flow of engagement, for fees see Schedule of fees, and for the overall picture of inheritance work see Inheritance, wills and trusts service.

FAQ

Q. One of the heirs has dementia. Can the other heirs hold the estate division discussion without them?
A. The estate division discussion is a procedure in which the co-heirs are the parties, and every person who is a party must take part. For a person whose capacity is insufficient, filing for commencement of guardianship, curatorship or assistance with the Family Court (Civil Code, Articles 7, 11 and 15) is one route to consider. Confirm the individual choice of procedure with an attorney.

Q. A child who became the adult guardian is also an heir. Can the discussion proceed as it is?
A. Civil Code Article 860 applies Article 826 mutatis mutandis to a guardian in respect of acts involving a conflict of interest, except where there is a supervisor of the guardian. Where there is a supervisor, the supervisor represents the ward (Civil Code, Article 851, item 4); where there is none, a petition for appointment of a special representative is filed with the Family Court.

Q. Is a special representative always needed when there is a minor child?
A. As to an act in which the interests of the father or mother exercising parental authority and the child conflict, the person exercising parental authority must request the appointment of a special representative from the Family Court (Civil Code, Article 826, paragraph 1). An estate division discussion where the person with parental authority is also an heir is given as an example of such an act in the courts' procedural guidance. Confirm the application to your case with the Family Court or an attorney.

Q. An heir is missing. Is nothing possible until seven years have passed?
A. Ordinary disappearance requires that the person's life or death has been unknown for seven years (Civil Code, Article 30, paragraph 1). By contrast, appointment of an administrator of an absentee's property (Civil Code, Article 25, paragraph 1) has no period requirement, and the appointed administrator may take part in the estate division with the Family Court's permission for an act exceeding authority. Confirm which route to take with an attorney.

Sources (Primary Information)

• Civil Code (Act No. 89 of 1896), Articles 4, 7, 10, 11, 15, 25 paragraph 1, 28, 30 paragraphs 1 and 2, 31, 826 paragraphs 1 and 2, 851 item 4, 860, 907 paragraph 1, 915 paragraph 1 and 951 (e-Gov, confirmed 22 August 2026; last amended by Act No. 45 of 2026, reflecting provisions in force as of 24 June 2026)
• Courts, "Commencement of guardianship" (accessed 22 August 2026) — filing fee revenue stamps of 800 yen, registration fee revenue stamps of 2,600 yen
• Courts, "Appointment of a special representative (conflict of interest between a person with parental authority and their child)" (accessed 22 August 2026) — revenue stamps of 800 yen per child
• Courts, "Appointment of a special representative (temporary curator or temporary assistant) concerning an adult ward, person under curatorship or person under assistance" (accessed 22 August 2026)
• Courts, "Appointment of an administrator of an absentee's property" (accessed 22 August 2026) — statement that estate division and the like are carried out after obtaining permission for an act exceeding authority
• Courts, "Adjudication of disappearance" (accessed 22 August 2026) — official gazette publication fee of 5,298 yen (3,359 yen demand plus 1,939 yen adjudication)
• Courts, "Appointment of an administrator for the liquidation of inherited property" (accessed 22 August 2026) — official gazette publication fee of 5,582 yen
• Judicial Scrivener Act, Article 3 / Attorney Act, Article 72 / Certified Public Tax Accountant Act, Article 52 / Administrative Scrivener Act, current provisions

This article is general information and does not guarantee the choice of procedure, whether a petition will succeed, costs, duration or the Family Court's decision in any individual case. Preparation of documents to be filed with the Family Court and inheritance registration are handled by a judicial scrivener or attorney; the choice of procedure, agency in a petition and disputed cases by an attorney; inheritance tax by a tax accountant; and sale appraisal and brokerage of real estate by Yotsuba Real Estate Co., Ltd., each as an independent business under a separate contract. Our office receives no referral fee. Individual judgements are made by a qualified professional after a meeting. Written by Joji Uramatsu, administrative scrivener and licensed real estate broker.