The Boy and the Beast (2015): The Reality Behind How Kyuta Tracked Down His Father

In Mamoru Hosoda’s acclaimed animated feature The Boy and the Beast (Official Website), there is a pivotal sequence where the protagonist, Kyuta (Ren), returns to the human world for the first time in eight years. Upon attempting to re-enter society, he discovers that his official “resident record” has been deleted by the government (a process known as ex officio deletion).

While navigating the bureaucratic maze to restore his resident record, he miraculously discovers the current address of his estranged biological father, leading to an emotional reunion. To an international audience—or even a casual viewer—this sudden discovery might seem like a lazy piece of “cinematic convenience” written just to move the plot forward.

However, when we analyze this exact sequence of events against real-world Japanese laws and municipal administrative procedures, it reveals a staggeringly realistic and brilliant piece of screenwriting.

In this article, we will break down the actual Japanese administrative mechanisms that allowed Kyuta to legally track down his father’s address.

*Note: While the following breakdown has been thoroughly researched, there may be slight legal nuances. Please enjoy this as a fascinating bit of trivia to deepen your appreciation of the movie!

*This is a translated version. The original (Japanese) is available here.

The Key is the “Supplementary Family Register” (Koseki no Fuhyo)

When Japanese citizens hear about procedures regarding official status, the first document that comes to mind is the “Family Register” (Koseki Tohon). However, the absolute key to Kyuta locating his father was not the standard Family Register, but a highly specific, secondary official document known as the “Supplementary Family Register” (Koseki no Fuhyo).

Obtaining this specific document wasn’t just a convenient plot device; it was a strict “procedural necessity” required to get his life back.

The Difference Between “Family Register” and “Supplementary Family Register”

To understand the genius of this scene, we first need to understand the decisive legal difference between these two Japanese documents.

The Main Differences Between “Family Register” and “Supplementary Family Register”

Document Name	Main Purpose (What it Proves)	Address Listing
Family Register (Koseki Tohon)	It legally proves family relationships. (e.g., Who the parents are, date of birth, marriage records)	Current address is NOT listed at all. (The “Registered Domicile” is listed, but this is a permanent family anchor point and often differs from where a person actually lives).
Supplementary Family Register (Koseki no Fuhyo)	It legally proves address history. (e.g., A timeline of exactly when and where a person has moved since the family register was created).	Current address IS listed. (Crucially, if you request a “Copy for All Members,” it lists the complete address history—from past to present—for *everyone* legally bound to that Family Register).

Working backward from the film’s events, the script strongly implies that despite his parents’ divorce, Kyuta legally remained under his father’s family registry. Therefore, when Kyuta requested the Supplementary Family Register as a “copy for all members,” the document automatically generated his father’s “latest address” (the registered location of his active resident record) because they still shared the same registry.

Why Did Kyuta Even Need the “Supplementary Family Register”?

So, why did Kyuta go out of his way to obtain the “Supplementary Family Register” in the first place? Because it was legally indispensable for the procedure of restoring (re-registering) his deleted resident record.

Because Kyuta had been officially missing for eight years, his resident record had been subjected to “ex officio deletion” (meaning the government wiped his record because they assumed he was gone). He was legally a ghost with “no fixed address.” To create a new resident record and rejoin human society, he was required to prove two things at the ward office counter:

Point 1, “Proof of Identity,” can be satisfied using a standard “Family Register.” However, Point 2, “Proof of Past Address History,” requires the “Supplementary Family Register.”

In other words, Kyuta did not go to the ward office with the intention of hunting down his father. He simply needed the “Supplementary Family Register” to complete the bureaucratic requirement to restore his own legal existence. As an unintended consequence of that exact paperwork, his father’s current address was handed to him on a silver platter. That is the brilliant, grounded truth behind the scene.

How Did He Clear the Biggest Hurdle: “Identity Verification”?

This raises one massive, glaring question. Whether you are requesting a “Family Register” or a “Supplementary Family Register,” Japanese ward offices strictly require some form of official “identity verification” (like a driver’s license or My Number card). Did Kyuta, a boy who had been living in a magical beast dimension for eight years, possess a valid photo ID?

Absolutely not. So, how on earth did he obtain highly sensitive, official documents without an ID?

There is a realistic, legal solution to this problem as well. It is known as “Oral Verification (Oral Examination).”

Many municipalities across Japan permit “identity verification through oral questioning” as a strict last resort for citizens who absolutely cannot present physical ID documents (such as victims of fires, domestic abuse fleeing their homes, or people who have been missing).

In this process, the municipal official pulls up the applicant’s “Family Register” information on their screen (Registered Domicile, Head of Household, Date of Birth, exact Kanji of parents’ names, etc.) and asks highly specific “security questions that only the actual person would know.” If the applicant answers the rapid-fire questions flawlessly, their identity is legally verified.

It is entirely realistic to assume that Kyuta—who was 9 years old when he disappeared and vividly remembered his family history—cleared the identity verification through this exact oral method to obtain his paperwork.

Reference: Official Municipal Guidelines on “Oral Verification”

To prove this isn’t just a theory, here are direct quotes from the official websites of multiple Japanese municipalities detailing the “Oral Verification” process:

English Translation:
(Note) When the above [physical ID] cannot be presented, we may supplement identity verification through oral questioning, so we ask for your cooperation.

(Original Text in Japanese)
（注）上記のものが提示できないときは、口頭での質問により補充的に本人確認することがありますので、ご協力ください。

Source: Sagamihara City “Question: I want to know how to obtain a copy of the Supplementary Family Register.“

English Translation:
If [ID] cannot be confirmed, we will perform identity verification through oral questioning.

(Original Text in Japanese)
確認できない場合は、口頭質問により本人確認を行います。

Source: Ise City “Fees for Family Register Related Certificates“

English Translation:
Those who do not have documents to verify identity can still apply for issuance, but we will verify identity through oral questioning or other documents.

(Original Text in Japanese)
本人確認ができる書類をお持ちでない方も交付申請はできますが、口頭での質問やその他の書類によって本人確認をさせていただきます。

Source: Kannami Town “Identity Verification When Applying for Resident Records and Family Register Certificates“

English Translation:
If you do not have documents to verify your identity, we will verify your identity by asking questions orally, etc.

(Original Text in Japanese)
本人確認できる書類をお持ちでない場合、口頭等で質問をすることで本人確認をさせていただきます。

Source: Toride City “Presentation of identity verification documents is required when submitting notifications regarding Family Registers or Resident Records, or applying for certificates“

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Summary: The Brilliant “Restoration of Resident Record” Sequence

By connecting the dots of Japanese bureaucracy, we can seamlessly infer the exact, realistic procedure Kyuta went through in the film:

When viewed through this lens, the scene in The Boy and the Beast is not a lazy plot hole. Provided we accept the baseline premise that he “remained in his father’s family registry,” it is a meticulously researched, highly realistic sequence.

Furthermore, the fact that Hosoda and his screenwriting team specifically engineered a narrative flow where Ren’s desire to take the “High School Equivalency Exam” requires him to get a “Resident Record,” which forces a “Re-registration,” which demands a “Supplementary Family Register,” which finally hands him his father’s address… is nothing short of Brilliant!

Reference: Why Was the Resident Record Deleted in the First Place?

For those curious about the initial premise: why was Kyuta’s resident record “deleted (ex officio deletion)” by the government to begin with?

This happens because Kyuta had been officially missing for eight years. The municipal administration eventually determined that there was “no reality of residence” at his registered address.

“Ex officio deletion” refers to a strict legal procedure under the Basic Resident Registration Act. A municipality possesses the administrative authority to forcibly delete a resident record when it conclusively determines that “the person does not actually live at the address listed.”

The administration doesn’t do this randomly. They confirm the “reality of residence” through a series of checks: massive amounts of returned mail, testimonies provided by neighbors or landlords, or cross-referencing system usage (such as zero activity on National Health Insurance). If someone vanishes for an extended period like Kyuta, the investigation concludes there is “no reality of residence,” and they are purged from the active system via ex officio deletion.

Many Japanese municipalities publicly list the concrete legal triggers for this deletion. Here is an example:

English Translation:
(Concrete Examples of Ex Officio Deletion)

1. When doubts arise regarding items listed in the resident record due to responses at the counter for resident record transfer tasks, etc.

2. When information regarding a person whose residence is unknown is provided by other departments such as the Tax Division, National Health Insurance Section, Elderly Welfare Division, or administrative agencies due to non-delivery of mail or home visits.

3. When there is a report or notification from relatives, cohabitants, nearby residents, house owners, or house managers that the person is a non-resident.

4. When a notification of moving in does not arrive from the municipality of the new address even after six months have passed since obtaining a moving-out certificate.

5. For foreign nationals, when there is a notification from the Ministry of Justice that they have returned to their home country or that their period of stay has expired.

In such cases, the Citizens’ Division conducts a factual investigation, and when it is determined that there is no reality of residence, ex officio deletion of the resident record is performed.

(Original Text in Japanese)
（職権消除の具体例）

①住民票異動事務の窓口の対応等で、住民票記載事項に疑義が生じた場合

②税務課や国民健康保険係、高齢者福祉課など他所管及び行政機関から、 郵便不達や臨戸訪問等により居住が不明な方の情報提供

③親族及び同居人、近隣の住民等、家屋の所有者又は家屋の管理人などから、 不現住者である旨の申し出や通報があった場合

④転出証明書を取得してから６ヶ月経過後においても、転入先の市区町村から 転入通知が届かない場合

⑤外国人の方で法務省からの帰国した旨の通知や、在留期間満了の通知 があった場合

などにより、住民課が実態調査を行い、居住の実態がないと判断した時に住民票の職権消除を行っております。

Source: Kawasaki Town, Fukuoka Prefecture “Ex Officio Deletion of Resident Record“

English Translation:
When residence at the address on the resident record cannot be confirmed, the city may perform deletion, entry, or correction by ex officio in accordance with laws and regulations.

(Original Text in Japanese)
住民票上の住所での居住が確認できないときなど、法令に則り市が職権による消除又は記載、修正を行うことがあります。

Source: Itoshima City “Let’s Register Residency Correctly.“

Because Kyuta vanished into the Beast Realm for nearly a decade, he fell perfectly into the category where “residence reality cannot be confirmed” (highly likely triggering investigations under cases 2 or 3). Therefore, his resident record was scrubbed completely in accordance with Japanese law—making his journey to restore it all the more fascinating.