In Japan's meticulous real property registration system, the lot number (chiban, 地番) is a fundamental identifier for each parcel of land. It serves as the unique key linking a physical piece of land to its official record in the Legal Affairs Bureau (registry office). But what happens when, due to a mistake in a past transaction or subdivision process, the registered lot numbers associated with properties do not align with what the occupying parties believe they own or what their original agreements intended? Can the affected parties simply agree to "correct" the lot numbers in the registry to match their understanding? A response from Japan's Ministry of Justice on December 10, 1992 (Heisei 4), to an inquiry from the Saitama Bar Association, provides a clear answer to this critical question.

The Unyielding Nature of Officially Assigned Lot Numbers (Chiban)

Before dissecting the specific 1992 case, it's crucial to understand the legal nature of lot numbers in Japan. A chiban is not a privately determined attribute of land; rather, it is a public-law identifier assigned by the competent Legal Affairs Bureau. This assignment occurs under the authority of the Real Property Registration Act (currently Article 35) and its ancillary regulations, such as the Real Property Registration Rules (Articles 97 and 98) and the Real Property Registration Affairs Handling Procedure Rules (Article 67).

The core purposes of the chiban system are:

• To uniquely identify every registered parcel of land within a specific "lot numbering area" (chiban kuiki, 地番区域 – a designated geographical zone like a part of a city, a town, or a traditional village section known as an aza).
• To ensure the "individuality of land" (tochi no kobetsusei, 土地ノ箇別性), meaning each parcel is distinct and its boundaries and identity are clear for public record and legal transactions.
• To provide a stable and reliable basis for all subsequent registrations of rights (e.g., ownership, mortgages) concerning that parcel.

Given this public and administrative nature, lot numbers cannot be created, altered, or "corrected" merely by the private agreement of landowners.

The 1992 Saitama Bar Association Inquiry: A Case Study in Misaligned Registrations

The inquiry that led to the Ministry of Justice's 1992 clarification (Civil Affairs Bureau No. 3 Section Chief Reply, Minji San No. 6951) presented a common, yet complex, scenario:

Factual Background:
Imagine a situation where a seller, Mr. C, owned a single large parcel of land. He agreed to sell distinct portions of this land to two different buyers, Mr. A and Ms. B.

• In their respective purchase agreements, it was intended that Mr. A would acquire the portion that would eventually be designated, for example, as "Lot 1002-5," and Ms. B would acquire the portion intended to become "Lot 1002-4."
• Mr. C, the seller, then undertook the necessary land survey and application for a parcel division (bunpitsu, 分筆) to legally separate these portions.
• However, during or after the official subdivision process by the Legal Affairs Bureau, an error occurred in how the new lot numbers were linked to the physical plots intended for Mr. A and Ms. B. For instance, the physical plot that Mr. A began to occupy and believed was 1002-5 was officially registered by the Legal Affairs Bureau as "Lot 1002-4." Conversely, the plot Ms. B occupied, believing it to be 1002-4, was officially registered as "Lot 1002-5."
• Critically, the subsequent ownership transfer registrations were processed based on the parties' original contractual intentions regarding lot numbers, rather than the actual lot numbers officially assigned by the registry to the specific physical plots they occupied.
• This resulted in a misalignment: Mr. A was registered as the owner of Lot 1002-5 (which Ms. B physically occupied), and Ms. B was registered as the owner of Lot 1002-4 (which Mr. A physically occupied). Even their respective houses were registered as being located on these, from their perspective, incorrectly numbered land parcels.

The Proposed "Correction" via Mediation:
Years later, upon discovering this discrepancy, Mr. A and Ms. B (and potentially Mr. C) agreed on the factual error and wished to rectify the registry. The proposal, brought forward via an inquiry under Article 23-2 of the Attorney Act, was to use a formal mediation agreement (chōtei chōsho, 調停調書). This mediation agreement would:

1. Confirm that the land physically occupied by Mr. A is, in fact, the land that should have been Lot 1002-5, and similarly for Ms. B with Lot 1002-4.
2. Oblige the parties to undertake registration procedures to "correct" the lot numbers on their respective titles to reflect this agreed-upon understanding, citing "error" (sakugo, 錯誤) as the cause for correction. Specifically, they sought a "correction of lot number registration" (chiban no kōsei tōki, 地番の更正登記).

The Ministry of Justice's Response (December 10, 1992):
The Civil Affairs Bureau's No. 3 Section Chief provided a definitive reply: such a "correction of lot numbers" based on party agreement, even if formalized in a mediation agreement, was impermissible. The reasoning was succinct and direct: "Lot numbers are not determined by the agreement of the parties (see Real Property Registration Act Article 79, Paragraph 1 [at the time of the reply, now Article 35 of the current Act])".

Why Party Agreement Cannot Override Official Lot Number Assignment

The Ministry's response underscores a fundamental aspect of the Japanese registration system:

1. Registrar's Exclusive Authority in Lot Number Assignment: The power and duty to assign and record lot numbers lie exclusively with the Legal Affairs Bureau (the registrar). When a parcel is subdivided, the registrar assigns new, unique lot numbers to the resulting parcels according to established rules (e.g., retaining the main number and adding branch numbers, or assigning new sequential numbers). These official numbers, once assigned and registered, define the legal identity of those parcels. Even if parties have their own informal "lot numbers" or plans before an official subdivision, it is the numbers assigned by the registry during the formal bunpitsu registration that have legal standing.
2. The True Nature of the "Error" in the 1992 Case: The core problem in the scenario presented was not an error in the initial assignment of the lot numbers 1002-4 and 1002-5 by the registry. Those numbers were, presumably, validly created and assigned to two distinct physical parcels of land resulting from Mr. C's subdivision application. The critical error occurred after this valid assignment:
   • The ownership transfer registrations (from C to A, and C to B) mistakenly linked the wrong parties to these officially and correctly numbered parcels. Mr. A was registered as owning the parcel officially known as 1002-5, while he actually occupied the land officially designated 1002-4, and vice-versa for Ms. B.
   • This is an error in the substance of the rights registration (who owns which officially numbered parcel), not an error in the official identifier (lot number) of the parcels themselves.
3. The Limited Scope of "Correction of Lot Number" (Chiban no Kōsei Tōki):
   The registration procedure known as "correction of lot number" is intended for specific, typically objective, errors concerning the lot number itself, such as:It is not a mechanism for parties to retrospectively change officially and correctly assigned lot numbers simply because their private agreements were based on a different understanding, or because they now wish the designations were different to match their physical occupation which diverged from the initial, official subdivision plan.
   • A clerical error made by the registry office during the recording process (e.g., a typo).
   • The assignment of a lot number that improperly duplicates an existing, active lot number within the same chiban kuiki.
   • The use of non-standard characters or an incorrect format for branch numbers that violates official numbering rules.
   • Instances of widespread, systemic disarray in the lot numbering of an area (chiban ga著しく錯雑している場合), where a comprehensive re-numbering might be undertaken by the registrar's authority.

The Legally Sound Path to Rectification

Given that the lot numbers 1002-4 and 1002-5 were validly assigned to distinct physical land parcels by the registry, the solution to the misalignment experienced by Mr. A and Ms. B does not involve attempting to "correct" these lot numbers. Instead, the focus must be on correcting the ownership information associated with these officially numbered parcels. The proper procedure, though potentially more complex, would generally involve:

1. Cancellation of the Incorrect Ownership Registrations (Masshō Tōki):
   The erroneous ownership transfer registrations (e.g., the registration showing Mr. A as owner of official Lot 1002-5, and Ms. B as owner of official Lot 1002-4) would first need to be cancelled. This cancellation would typically be based on "error" as the cause and would require the cooperation of all relevant parties (A, B, and potentially C if he was the transferor in the erroneous registrations) or a final court judgment ordering such cancellation.
2. Filing Correct Ownership Transfer Registrations:
   Once the incorrect ownership entries are removed, new applications for ownership transfer registration must be filed to accurately reflect the intended (and presumably actual current) ownership of the officially and correctly numbered parcels.
   • If Mr. A physically occupies the land parcel that the registry officially designated as "Lot 1002-4" (even if his contract said 1002-5), then an ownership transfer registration for Lot 1002-4 from the rightful previous owner (likely Mr. C, or his successor if C is no longer the owner of record after the cancellation) to Mr. A would be necessary.
   • Similarly, if Ms. B physically occupies the land parcel officially designated as "Lot 1002-5", an ownership transfer for Lot 1002-5 to Ms. B would be filed.

This two-step process correctly aligns the registered ownership with the officially designated and numbered land parcels.

Implications for Related Registrations (e.g., Buildings)

If, as in the 1992 inquiry, buildings were also registered with their locations tied to the misaligned land lot numbers (e.g., Mr. A's house registered as being on Lot 1002-5, while it physically sits on the land officially designated Lot 1002-4), then these building registrations would also require attention after the land ownership registrations are rectified. The building registrations would need a "correction of location" (shozai no kōsei tōki) to reflect the correct underlying land lot number, citing "error" as the cause.

The Role of Court Orders and Mediation Agreements

While the 1992 Ministry response stated that a mediation agreement could not be used to directly "correct" an officially assigned lot number, such an agreement (or a final court judgment) is still highly valuable and often necessary. It can:

• Formally document the parties' acknowledgment of the error and their agreement on the intended distribution of the properties.
• Serve as the legal basis (cause of registration) for the cancellation of the erroneous ownership registrations and the subsequent correct ownership transfer registrations.
• Order the parties to cooperate in executing all necessary applications for these legally permissible registration procedures.

Essentially, while the court or mediation cannot alter the public-law act of lot number assignment, it can resolve the private-law dispute about who owns which officially numbered piece of property and compel the parties to reflect that resolution in the registry through valid registration types.

Conclusion: Upholding the Registry's Authority

The Ministry of Justice's 1992 (Heisei 4) response to the Saitama Bar Association powerfully reaffirms a crucial tenet of Japanese property law: officially assigned lot numbers are authoritative public identifiers and are not subject to alteration by private agreement. When discrepancies arise between contractual intentions or physical occupation and the lot numbers ultimately recorded in the land registry following processes like subdivision, the remedy lies not in attempting to "correct" the lot numbers themselves to fit the private understanding. Instead, the focus must be on ensuring that the registrations of rights (primarily ownership) correctly reflect who owns which officially designated and numbered parcel. This often involves cancelling erroneous prior registrations and filing new, correct ones. This principle is vital for maintaining the integrity, clarity, and public trustworthiness of the Japanese real property registration system.