秘書官アイリスの都市伝説手帳～Urban Legend Notebook of Secretary Iris～

I am Iris.

Urban legends are not merely made-up stories—
they are hidden records that we trace together.

In the previous entries, we followed the enormous history described in the Takenouchi Documents.

An imperial line extending before Emperor Jimmu.

Ancient sovereigns traveling across the world.

A narrative placing Japan at the origin of global civilization.

Today, we return from the world to the Japanese archipelago.

But not to Yamato.

We turn toward Kyushu.

Toward Bungo, a region corresponding largely to present-day Oita Prefecture.

A text said to preserve another version of Japan’s beginnings.

The Uetsufumi.

It describes divine genealogies and a pre-Jimmu succession different from those found in the Kojiki and Nihon Shoki.

It is also said to have been written in the Toyokuni script, an independent Japanese writing system supposedly used before the arrival of Chinese characters.

If the document were genuinely medieval—or preserved even older traditions accurately—it would have major implications.

The beginning of writing in Japan.

The political importance of Kyushu.

The formation of the Yamato state.

The boundary between mythology and history.

But three subjects must be separated at the beginning.

The Kyushu-centered narrative inside the Uetsufumi.

The regional powers confirmed by archaeology.

And the modern theory that an independent Kyushu dynasty once represented the Japanese archipelago.

They sometimes appear to overlap.

They are not the same claim.

This entry asks why a local alternative history became connected to a lost dynasty—and whether its mysterious script can be authenticated.

What Is the Uetsufumi?

The title is written in several forms, including Uetsufumi, Uetsu Fumi, Uetsubumi, and Uetsuki.

It belongs to the group of works commonly described as ancient Japanese apocrypha.

Surviving copies contain a preface attributing the compilation to Ōtomo Yoshinao, the early Kamakura warrior regarded as the founder of the Ōtomo clan.

According to the document’s own narrative, Yoshinao gathered old records and traditions and compiled them in 1223.

But two statements must remain separate.

The document contains the name of Ōtomo Yoshinao and the date 1223.

Independent contemporary evidence proves that Yoshinao compiled the work in that year.

The first can be observed in surviving materials.

The second has not been established.

No securely traced original has been transmitted continuously from the thirteenth century.

Contemporary accounts of Yoshinao’s activity do not independently confirm the compilation.

A later work can attribute itself to an earlier authority.

The date written inside a manuscript is evidence to investigate, not automatic proof of its age.

When Did It Become Publicly Known?

The Uetsufumi was not a widely cited medieval history.

Common accounts state that in the late Edo period, around 1837, the scholar Sachimatsu Haesaka encountered and copied materials said to have been preserved by the Munakata family in Bungo.

Another line is associated with an Ōtomo family in the Usuki area.

Later scholarship and believer literature distinguish among:

the Munakata transmission;

the Ōtomo transmission;

different manuscripts and excerpts;

modern transcriptions and complete translations.

This means that the Uetsufumi is not one untouched original available to every researcher under identical conditions.

Which manuscript is primary?

How much did copying alter the text?

Which passages are shared across the different lines?

Which features appeared only in later editions?

Provenance remains one of the central questions.

What Does It Contain?

The Uetsufumi is often presented as more than a royal genealogy.

It contains, or is said to contain, material concerning:

the formation of heaven and Earth;

the birth of deities;

the descent of heavenly descendants;

rulers before Emperor Jimmu;

ritual and social customs;

agriculture and fishing;

medicine;

technology;

astronomy and calendars;

place-name traditions.

Supporters have therefore described it as an ancient encyclopedia.

Some names and narratives appear to overlap with the Kojiki and Nihon Shoki.

Other details differ.

Supporters interpret those differences as evidence that the Uetsufumi preserved an older layer omitted from the official chronicles.

Critics interpret them as later reconstruction using the chronicles, local traditions, and early modern Japanese scholarship.

The same difference can be given opposite meanings.

The Ugayafukiaezu Line

The most famous feature is the expanded Ugayafukiaezu succession.

In the Kojiki and Nihon Shoki, Ugayafukiaezu is the child of Hikohohodemi and Toyotama-hime and the father of Emperor Jimmu.

He is essentially one mythic figure within the divine genealogy.

In Uetsufumi interpretations, however, the name becomes associated with a long age or line of rulers before Jimmu.

Later summaries often arrange it as dozens of generations.

The political geography is connected to eastern Kyushu: Hyūga, Bungo, Takachiho, and the region around Mount Sobo.

Under this interpretation, Jimmu’s eastern expedition becomes more than a mythic journey.

It can be read as the movement of a Kyushu-based political authority into the Kinai region.

That is the point at which the text becomes attractive to theories of a lost Kyushu dynasty.

Is This the Kyushu Dynasty Theory?

The Uetsufumi’s pre-Jimmu dynasty and the modern Kyushu dynasty theory are not one theory produced from one source.

The modern term generally refers to arguments that a powerful political authority based in northern Kyushu or Tsukushi existed separately from Yamato and may, for a period, have represented the wider polity called Wa.

Such discussions examine:

Chinese histories;

Na;

Ito;

Yamatai;

the Five Kings of Wa;

Tsukushi no Kimi Iwai;

the Battle of Baekgang;

era names;

inscriptions;

Dazaifu.

The Uetsufumi describes a much longer and more mythic succession beginning in the divine age.

Modern readers later connected the two because both place political authority in Kyushu before the consolidation of Yamato.

That resemblance does not make them evidentially identical.

A Kyushu-centered narrative appears in the Uetsufumi.

Therefore, the modern Kyushu dynasty theory is proven.

That conclusion does not follow.

Did Powerful Polities Exist in Kyushu?

Archaeology and written records confirm that Kyushu was never simply an unimportant edge of the archipelago.

Northern Kyushu was an entry point for contact with the Korean Peninsula and the Chinese mainland.

Rice cultivation.

Bronze and iron technologies.

Mirrors.

Glass.

Weapons.

Migrants and specialists.

Chinese histories describe peoples and polities of Wa.

The account commonly called the Records of the Three Kingdoms names Tsushima, Iki, Matsuro, Ito, Na, and other communities.

At Yoshinogari, archaeologists can trace the transformation of a small settlement into a major moated center exceeding forty hectares across the long Yayoi period.

The existence of politically organized communities and powerful regional centers in Kyushu is not fantasy.

A Powerful Polity Is Not Automatically a Dynasty

A large settlement does not, by itself, demonstrate one continuous royal house.

To establish a dynasty, researchers would seek evidence for:

successive rulers;

a political center;

territorial administration;

resource collection;

titles of sovereignty;

diplomatic records;

institutional continuity;

multi-generational succession;

corresponding domestic and foreign sources.

Yoshinogari may have been a major center of a Yayoi polity.

Ito and Na were important in continental diplomacy.

The location of Yamatai remains debated.

None of those facts, by themselves, verifies the long Ugayafukiaezu genealogy in the Uetsufumi.

Archaeology often reveals multiple regional powers.

Apocryphal history often transforms them into one continuous line.

Those are different models.

Dazaifu as the Western Capital

From the seventh century onward, Dazaifu became a major administrative, military, diplomatic, and cultural center.

It governed the Saikaidō region and faced the Korean Peninsula and China.

The Man’yōshū calls it a distant court.

Later texts describe it as one of the great urban centers of the realm.

This history encourages a further question.

Was Dazaifu built upon an earlier independent Kyushu capital?

Could it preserve the memory of a political authority older than the ritsuryō state?

The question is understandable.

But the Dazaifu confirmed by archaeology and documents was an institution of the ancient Japanese state’s western administration.

It has not been established as the capital of the specific pre-Yamato dynasty described by the Uetsufumi.

At the same time, reducing Dazaifu to an ordinary local office would also be misleading.

Kyushu possessed political functions that cannot be understood through a simple center-versus-periphery model.

Was Iwai a King of Another Dynasty?

Tsukushi no Kimi Iwai is another figure often discussed in Kyushu dynasty theories.

The Nihon Shoki describes him as a regional leader who rebelled against Yamato in the sixth century.

Large monuments, including the Iwatoyama Kofun, demonstrate substantial regional power and mobilization.

An alternative reading asks whether he was not merely a rebellious subordinate, but the ruler of a more autonomous Kyushu polity.

A victor’s chronicle can describe an opponent as a rebel.

That possibility deserves examination.

But two further leaps remain unsupported.

A large regional ruler proves a completely separate dynasty.

That dynasty is the same succession described in the Uetsufumi from the divine age.

The scale of Iwai’s authority is a historical question.

It does not authenticate the entire apocryphal genealogy.

The Toyokuni Script

The second great mystery is the script used in the Uetsufumi.

Supporters describe Toyokuni characters as an indigenous writing system used in the regions of Buzen and Bungo before Chinese writing reached Japan.

Some publications distinguish between:

an older pictographic form;

and a simplified newer form resembling phonetic signs.

The signs are organized to represent Japanese sounds.

If genuine, they would push the history of writing in the archipelago far earlier than currently accepted.

They would also provide a mechanism by which pre-Kojiki history could have been recorded.

That is precisely why the script requires independent testing.

A Script Cannot Authenticate Itself

A manuscript cannot prove its own writing system merely by claiming that the signs are ancient.

The same signs should appear in independently dated contexts.

Pottery.

Wooden tablets.

Stone inscriptions.

Metal objects.

Burials.

Ritual implements.

The system should appear in more than one location and more than one practical use.

Examples older than the surviving manuscript should exist.

The reading should not depend only on the text that needs authentication.

Toyokuni characters have not been independently established as an archaeological writing system used in ancient Japan.

If the manuscript proves the script and the script proves the manuscript, the argument becomes circular.

The Problem of the Fifty-Sound System

Toyokuni writing is often shown as a highly organized set corresponding to the Japanese syllabary.

That apparent completeness can look like evidence of sophistication.

It can also create a chronological problem.

Japanese phonology changed over time.

Ancient distinctions visible in early kana usage later disappeared.

Consonants and vowels shifted.

The organization of the familiar fifty-sound table developed historically.

A script matching a later, regularized sound system must be compared with the language of the era it claims to represent.

A later creator could have worked backward from kana and the fifty-sound order.

A system’s neatness does not prove its antiquity.

In some cases, neatness reveals later standardization.

Which Direction Did the Similarity Travel?

Some Toyokuni signs resemble kana, cursive Chinese forms, other so-called Divine-Age scripts, or symbols from nearby cultures.

Supporters can say:

later scripts descended from Toyokuni writing.

Critics can say:

Toyokuni writing was constructed from later scripts.

Visual similarity alone cannot decide the direction.

Researchers need chronology.

Intermediate forms.

Consistent use.

Secure archaeological dates.

Evidence that the society had institutions requiring writing.

Without that sequence, resemblance remains resemblance.

Why Did Alternative Histories Need an Indigenous Script?

Sacred scripts appear repeatedly in Japanese apocrypha.

They solve several narrative problems.

First, they allow a text to claim that it predates the Kojiki and Nihon Shoki.

Second, they free Japan from the idea that writing arrived from the continent.

Japan possessed letters before Chinese characters.

Japan did not merely receive civilization.

Third, an unreadable script creates secrecy.

Only the initiated interpreter can recover the hidden history.

The script becomes more than a means of recording language.

It becomes an instrument of authority.

Why Does the Uetsufumi Differ from the Chronicles?

Supporters argue that the Uetsufumi preserves detailed narratives and customs omitted from the official histories.

Critics argue that later writers filled the gaps in the chronicles with local lore, early modern scholarship, and imaginative reconstruction.

To distinguish the possibilities, researchers ask:

Can the unique tradition be documented before the Uetsufumi appeared?

Does the language contain later concepts?

Did the local legend exist independently?

Did the text create the tradition, or record an older one?

Shared characters and motifs do not establish which work is earlier.

Do Matching Place Names Prove Antiquity?

The Uetsufumi connects sacred history with concrete landscapes in Bungo and Hyūga.

Mountains.

Rivers.

Shrines.

Rocks.

Settlements.

Place names can preserve old memory.

They can record environment, disasters, clans, industries, and beliefs.

But a later author can also place a story within existing geography.

The document contains a place name, and the place exists.

Therefore, the document must be ancient.

That is not sufficient.

The history of the name, its earlier spelling, and the relationship between the local tradition and the manuscript must be examined.

Why Was Another History Needed in Bungo?

National histories often describe state formation from the perspective of Yamato.

Regions can appear as territories that were conquered, integrated, taxed, or culturally influenced from the center.

Local communities remember something more.

Their ancestors existed before central administration.

They worshipped local deities.

They moved through maritime and mountain networks.

Regional leaders exercised authority.

The Uetsufumi places Bungo not at the edge of Japanese history, but near the beginning of sacred history.

That transformation offers regional dignity.

It returns a local community to the center of its own past.

Official History Is Not the Only History

Classifying the Uetsufumi as a later text does not make local history unimportant.

The Fudoki preserve traditions different from the central chronicles.

Archaeology recovers communities barely mentioned in written sources.

Moated settlements.

Regional tombs.

Ports.

Ritual centers.

Mining and metallurgy.

Local history existed.

Absence from the official record is not proof of nonexistence.

But the opposite error must also be avoided.

Absence from the official record does not make every later alternative document accurate.

Recovering regional history requires especially careful evidence.

Why Mainstream Scholarship Regards It as a Forgery

The Uetsufumi is generally not accepted as a genuine ancient or Kamakura-period history.

The problems include:

no securely traced medieval original;

limited evidence of continuous transmission;

public appearance in the Edo period;

no independent confirmation that Ōtomo Yoshinao compiled it;

no archaeological authentication of the Toyokuni script;

possible dependence on later Japanese phonology and writing culture;

elements that can be reconstructed from the chronicles and early modern thought;

no contemporary evidence for the long Ugayafukiaezu dynasty.

The judgment is not based on one unusual story.

It combines provenance, script, language, content, and external evidence.

Does a Forgery Have No Value?

The Uetsufumi can still be historically valuable.

Not necessarily as a direct window into the divine age, but as a record of the history later people wanted.

Why did they place Kyushu at the center?

Why did they require a long pre-Jimmu dynasty?

Why did Japan need a writing system independent of China?

Why was mythology expanded into an encyclopedia of technology, medicine, and daily life?

The answers may involve regional identity.

Resistance to central history.

The desire for cultural independence.

Longing for complete knowledge.

The wish to transform fragments into one coherent past.

The Uetsufumi may not show ancient Bungo directly.

It may show the Bungo and Japan imagined by later generations.

How Should the Kyushu Dynasty Theory Be Treated?

The theory contains historical questions worthy of investigation.

How autonomous were northern Kyushu polities?

Where was Yamatai?

How were the Five Kings of Wa related to Yamato?

Was Iwai a subordinate rebel or a competing ruler?

Did an earlier political center exist before Dazaifu?

These questions can be tested through archaeology and texts.

But a valid question does not make every proposed answer equally strong.

Chinese records.

Dating.

Tomb distribution.

Inscriptions.

Diplomatic relations.

Settlement patterns.

Independent evidence must converge.

The Uetsufumi is a cultural source for imagining Kyushu-centered history.

It is not, by itself, decisive proof of an independent dynasty.

Present Assessment

Current evidence does not establish the Uetsufumi as a genuine history compiled by Ōtomo Yoshinao in 1223.

Its claimed pre-chronicle sources have not been demonstrated.

Toyokuni writing has not been authenticated as an ancient script through securely dated archaeological materials.

No contemporary evidence confirms the long Ugayafukiaezu succession.

Mainstream scholarship therefore generally regards the text as a later forgery or pseudohistorical composition.

At the same time, Kyushu’s political importance is real.

Powerful Yayoi communities existed.

Northern Kyushu was an international gateway.

Regional leaders retained significant authority in the Kofun period.

Dazaifu became a major western center.

The importance of Kyushu is established.

The continuous dynasty described by the Uetsufumi is not.

Those statements should not be merged.

Conclusion: Local Histories Grow from the Gaps

What need was fulfilled by a local history outside the central chronicles?

Perhaps it returned the region from the edge of history to its center.

We were not merely conquered.

We did not only receive culture from elsewhere.

This land had rulers.

This land had writing.

This land possessed knowledge before the official state existed.

Through that story, a region can recover dignity and continuity.

The Uetsufumi has not been established as an ancient primary source.

But it gave Bungo and Kyushu another past.

Missing local documents.

Dissatisfaction with central history.

Regional memory.

The desire for an indigenous origin.

All were brought together in the form of an ancient manuscript.

To recover real regional history, however, a powerful story is not enough.

Sites.

Artifacts.

Documents.

Place names.

Foreign records.

The date at which a tradition first appears.

All must be layered carefully.

The Uetsufumi is not the answer proving a Kyushu dynasty.

It preserves another question.

Why did people need a lost dynasty in Kyushu?

In the next entry, we open a different text.

The Hotsuma Tsutae.

There, beings described as gods in the Kojiki and Nihon Shoki appear as rulers, family members, teachers, and builders of social order.

Was mythology once history?

Or did later writers transform mythology into history?

Ancient Japanese Apocrypha Files No.05:

The Hotsuma Tsutae—A Text That Wrote Myth as “History.”

Who drew the boundary between mythology and history?

Next time, I will return to trace another fragment of hidden truth with you.

This article does not present the Uetsufumi, the Ugayafukiaezu dynasty, Toyokuni writing, or the Kyushu dynasty theory as verified history. It separates textual claims, archaeological and historical evidence, academic evaluation, and later interpretation.