Inheritance Division Agreement in Japan — How to Draft It, Required Documents, and Getting All Heirs to Sign

An Inheritance Division Agreement (遺産分割協議書, Isan Bunkatsu Kyōgisho) is the legal document that records the agreed terms among all heirs for distributing the estate. When someone dies without a valid will in Japan, all legal heirs must jointly negotiate who receives which assets — a process called isan bunkatsu kyōgi (遺産分割協議). The resulting agreement, signed and sealed by all heirs, is required for bank procedures, property registration, and tax filing, among other matters.

When You Will Need the Agreement

What the Agreement Must Include

• Deceased person's details: Full name, date of death, last registered domicile (honsekichi), last address
• All heirs' details: Full name, address, date of birth
• Agreed distribution of each asset:
  • Real estate: Must match the exact description in the property register (location, lot number, land category, area; building number, etc.)
  • Bank accounts: Institution name, branch name, account type, account number
  • Securities: Brokerage name, security name, quantity
  • Treatment of other assets and liabilities
• Personal signatures and registered seal impressions from all heirs: Signatures must be handwritten; certified seal certificate (印鑑証明書) from each heir is required
• Date of agreement

Key Pitfalls to Avoid

• All heirs must participate: If even one heir is missing (no signature or seal), the agreement is invalid. If an heir's whereabouts are unknown, a court-appointed property administrator or declaration of disappearance may be needed.
• Heir with dementia: If an heir lacks legal capacity, a court-appointed adult guardian must represent them in the negotiation.
• Minor heir: A parent can normally act as representative, but if the parent is also an heir, a special representative (特別代理人) appointed by the family court is required to avoid a conflict of interest.
• Accurate property descriptions are critical: Use the exact wording from the property register. Errors can cause the registration application to be rejected.
• Multiple pages need a "straddle stamp" (契印): A seal impression spanning every page prevents substitution or tampering.

When Heirs Cannot Reach Agreement

If the heirs cannot agree, any heir may apply to the Family Court for a mediation (調停) on inheritance division. If mediation fails, the court issues a ruling (審判). The most reliable way to avoid such disputes is for the deceased to have left a valid will prepared in advance.

How Sakura Central Legal Office Can Help

We draft Inheritance Division Agreements, coordinate with judicial scriveners for property registration, and assist with will preparation. We also handle family register collection and heir identification. Free initial consultation available.