JapanCan I leave all to one person? Reserved shares?
Yes, you can leave all your estate to one person in Japan, but certain close relatives have legally protected 'reserved shares' (forced heirship rights) that cannot be fully disinherited.
What the Law Says
Japanese inheritance law guarantees certain family members a minimum portion of the estate—called the 'reserved share' (iryōbun)—even if a will attempts to exclude them. These rights apply automatically and cannot be waived in advance.
Under the Japanese Civil Code, statutory heirs—including spouses, children, and parents—have reserved shares that protect them from total disinheritance. The size of the reserved share depends on who survives the deceased.
If the only heirs are the spouse and children, each child is entitled to half of what they would have received under intestate succession, and the spouse is entitled to one-third. If only the spouse and parents survive, the spouse’s reserved share is one-half, and each parent receives one-fourth.
A person who believes their reserved share has been infringed may file a claim for reduction (kangen seikyū) against the beneficiary named in the will. This claim must be made within two years from when the heir becomes aware of both the inheritance and the infringement.
Statutory TextA person who has a right to a reserved portion may make a claim for reduction of gifts or bequests which infringe upon that right.
— Civil Code, s. 1031 — Reduction of Gifts or Bequests Infringing Reserved Portion
Statutory TextThe reserved portion of a child or a grandchild who succeeds by representation is one-half of the portion of the inheritance which he would have received had there been no will.
— Civil Code, s. 1028, para. 1 — Reserved Portion of Child or Grandchild
Statutory TextThe reserved portion of a spouse is one-third of the portion of the inheritance which he or she would have received had there been no will.
— Civil Code, s. 1028, para. 2 — Reserved Portion of Spouse
Statutory TextThe reserved portion of a parent is one-fourth of the portion of the inheritance which he or she would have received had there been no will.
— Civil Code, s. 1028, para. 3 — Reserved Portion of Parent
What to Do
Identify your statutory heirs (spouse, children, parents) before drafting your will.
Calculate each heir’s reserved share using Civil Code §1028 to assess whether your intended distribution complies.
If you wish to reduce a child’s or spouse’s share, consult a Japanese attorney—partial disinheritance is possible only with valid legal grounds (e.g., serious misconduct), and even then, reserved share claims may still apply.
File your will with the Legal Affairs Bureau (Hōmushō Hōjimukyoku) or use a notarized will to ensure enforceability.
Inform heirs of your intentions early—though not legally required, it helps prevent disputes and allows time for reserved share claims to be resolved promptly.
Sources
Same Question, Other Jurisdictions
Germany
Canada
Singapore
India
South Korea
US-California
US-New YorkNot legal advice. This article is general information based on publicly available sources, written for educational purposes. Laws change and individual situations vary. Consult a licensed attorney in your jurisdiction before acting on anything you read here. Last reviewed: 2026-06-08.