[2026 Latest] Top 3 Ranking of Ghostly Rumors Around Water in Yamaguchi Prefecture

This article focuses on three locations in Yamaguchi Prefecture—Toyoda Lake, Ono Lake, and Sugano Dam—based on rumors surrounding these waterfront areas. We will compare each specific claim made on the rumor-sharing pages with dam documents released by Yamaguchi Prefecture, and record the factual information about the facilities that can be confirmed, as well as the claims of strange occurrences that cannot be determined from the documents.

Survey methods and evaluation criteria

The investigation date was September 28, 2026. For each location, we re-obtained the direct page of the National Haunted Map, the source of the external rumors, and confirmed the Yamaguchi Prefecture River Division's dam overview page as another official document. We also compared specific claims such as name, location, purpose, and completion date, and did not use the mere presence of a rumor as proof of the phenomenon. The judgments were categorized into five types: Match (all confirmed claims are supported), Partial Match (supported and unconfirmed claims coexist), Discrepancy (direct counter-evidence exists regarding the subject or date), Unmeasurable (insufficient materials for direct comparison), and New Fact (meaningful official facts not found in the rumors were confirmed, while comparison is not possible). The document quality score was calculated on five axes: source transparency, historical/spatial context, safety information, recency of information, and source transparency of the rumor, and did not rank the truthfulness or danger level of the paranormal phenomena. The maps were fixed with the confirmed coordinates as Google Maps embeds and search links using the same values.

1st Place: Toyoda Lake | Partial Agreement (89 points)

The rumored details

The November 17, 2021 update page of the National Haunted Map describes Toyoda Lake as "a lake (pond) and dam located in Shimonoseki City, Yamaguchi Prefecture," and introduces the rumor that "a female ghost appears there." The text also explains that locals avoid the area after dark, that passing by the lake at night gives off an eerie feeling and makes one want to stay away, and that a nearby abandoned hotel was demolished due to an increase in intruders. The page's personal experience section has 0 stories, and the existence of votes and comments only indicates the spread of the rumor and does not constitute a record of officially confirmed phenomena.

Source of the rumor and date of verification

The external source is the Toyoda Lake direct page on the National Haunted Map, and the update date displayed at the time of verification was November 17, 2021. The rumors, votes, and comments on the page were read separately as records from the same source, and since it was not possible to confirm the primary source indicating the first appearance, it is treated as a secondary publication example/first appearance unknown.

• Nationwide Haunted Spot Map: "Toyoda Lake | Toyotako - Haunted Spot in Yamaguchi Prefecture"(Verification date: 2026-09-28) — The article lists "a female ghost appearing" as one of the "supernatural phenomena rumored to occur at Lake Toyoda," and includes a description that one can feel an unusual atmosphere when passing near the lake at night.

Things that could be confirmed from official and primary source materials

The Yamaguchi Prefecture River Division's "Koyagawa Dam" page clearly refers to the Koyagawa Dam as "Koyagawa Dam (Toyotako)". Its location is listed as Toyoda-cho, Shimonoseki City, Yamaguchi Prefecture, its completion date was March 1955, its management is handled by the Yamaguchi Prefecture Civil Engineering and Construction Department, and its contact information is the Koyagawa Dam Management Office. Toyoda Lake was designated a Toyota Prefectural Natural Park in 1962, and Toyoda Lakeside Park was opened in 1995, with information indicating facilities such as a campsite and walking trails. The reasons for the female ghost, the strange atmosphere, and the hotel demolition are not mentioned on the official page.

• Koya River Dam, Yamaguchi Prefecture(Confirmed on 2026-09-28) — It is listed as "Koyagawa Dam (Toyotako Lake)," with its location in Toyoda-cho, Shimonoseki City, Yamaguchi Prefecture, its completion date in March 1955, and its management division as the Yamaguchi Prefectural Department of Civil Engineering and Construction.

Points of agreement/contradictions

Official documents confirm that Lake Toyoda is the reservoir of the Koya River Dam and is located in Toyoda-cho, Shimonoseki City, thus supporting the name, location, and waterfront aspect. On the other hand, the female ghost, the feeling of wanting to stay away from dark places, and the reason for the demolition of the abandoned hotel are not mentioned on the official page, so they cannot be used to either support or refute. The classification is partially consistent, but this only means that the identification of the facility is partially supported, and does not constitute a judgment that supports the existence of a supernatural phenomenon.

The rumored atomic claim	Matching results	reason	Corresponding documents
Toyoda Lake is described as "a lake (pond) and dam located in Shimonoseki City, Yamaguchi Prefecture."	support	The official Yamaguchi Prefecture website lists the Koya River Dam and Toyoda Lake as the same reservoir and also indicates the location of Toyoda-cho in Shimonoseki City, so the identification of the subject of the rumor can be supported.	Koya River Dam, Yamaguchi Prefecture
A female ghost appears	Unconfirmed	The official dam overview obtained from the prefecture describes the facility's name, purpose, nature park, and park usage, but it does not record any appearance or sighting of a female ghost.	No official data available for direct comparison.
A nearby abandoned hotel was demolished due to an increase in trespassers.	Unconfirmed	Official documents regarding the Koya River Dam do not contain any information to support the existence of the hotel, the increase in intruders, or the reason for its demolition, so the facts cannot be confirmed based solely on the page containing the rumors.	No official data available for direct comparison.

Alternative interpretation

In mountain lakeside areas, nighttime fog, shade from trees, scarcity of cars, and echoes of sound can all contribute to feelings of unease. The official documents regarding the nature park and its use can be interpreted as a separate context that doesn't necessarily link the nighttime impression to paranormal phenomena, but it's impossible to determine the cause of the experience based solely on these documents.

Scope and limitations of the investigation

The official page I checked focuses on facility information for the dam and lakeside park, and is not an accident log or building record investigating the woman's sighting or the hotel's history. I have not reconfirmed the demolition date of the abandoned hotel mentioned on the rumor page, the first appearance of the rumor, or individual nighttime experiences with independent sources, so I will not treat the unconfirmed parts as inconsistencies.

Verification results: Partial match

The name Toyoda Lake, its location in Toyoda-cho, Shimonoseki City, and its relationship to the Koya River Dam were supported by official documents from Yamaguchi Prefecture. However, the female ghost, the eerie atmosphere, and the reason for the demolition of the abandoned hotel remain unconfirmed due to the lack of comparable official records. Therefore, the facility's response alone is not sufficient to establish a supernatural occurrence, and it is judged to be a partial match.

Document Quality Score

Source transparency	29/30	The prefectural river management division's individual dam information was highly commendable because it included the name, location, completion year, and administrator, and the rumor page also showed the update date and specific descriptions.
Historical and spatial context	23/25	Because official records allow us to trace the dam's completion year, the designation of Toyoda Lake as a prefectural natural park, and the opening date of the lakeside park, it's easy to compare the context of the space.
Safety information	17/20	The official website shows park facilities such as campgrounds and walking trails, and the rumors page also warns against unauthorized entry, making it possible to specify precautions for using waterfront areas.
Newness of information	12/15	Although the rumor page is outdated, the dam overview for Yamaguchi Prefecture was updated on May 24, 2023, making it relatively recent official information that can be used for identifying facilities.
Transparency of the source of rumors	8/10	While the specific details of the rumor, the publication date, and the state of the submission section can be read, the original source material and independent corroboration of individual experiences are not provided.
total	89/100	This is the overall quality of the materials. It does not represent the degree of truthfulness or danger associated with the supernatural phenomena.

Safety information and maps

While official prefectural documents state that Toyoda Lakeside Park has a campsite, observation rest area, and walking trails, this information does not authorize entry into the dam management area or private land. Visibility and footing are poor at night along the waterfront, and the rumor page also prohibits entry by unauthorized persons and trespassing, so we will only verify publicly available information.

Check the area around Toyoda Lake on Google Maps.

2nd place: Onoko | Partial match (87 points)

The rumored details

The December 16, 2023 update page of the National Haunted Map describes Ono Lake as "a lake (pond) and dam located in Ube City, Yamaguchi Prefecture," and notes that "a ghost of a young girl appears there." The text includes a series of rumors: a story about a girl, about the age of a third-grader, standing on the lake's surface at night and waving; a story about a ghost consisting only of an upper body chasing a car; and a description of an old tunnel that is "now a cut-through tunnel that has disappeared." The personal experience section has 0 stories, and the news section displays "No news," so the listing itself cannot be treated as evidence of an incident.

Source of the rumor and date of verification

The source of the rumors about Lake Ono is the direct page of the National Haunted Map, with the displayed update date being December 16, 2023. The appearance of the girl, the description of being chased by a car, and the history of the old tunnel are included as claims in the page text, and submitted videos and comments are not counted as independent evidence. The initial interview record cannot be confirmed from the page, so this is an example of secondary publication/original source unknown.

• Nationwide Haunted Places Map: "Ono Lake | Onoko - Haunted Spot in Yamaguchi Prefecture"(Verification date 2026-09-28) — It mentions that "the ghost of a young girl appears," and includes rumors of a girl standing on the surface of a lake, a torso-only figure chasing a car, and the disappearance of an old tunnel.

Things that could be confirmed from official and primary source materials

The Yamaguchi Prefecture River Division's "Kotogawa Dam" page clearly states "Kotogawa Dam (Ono Lake)," its location as Kida, Ube City, Yamaguchi Prefecture, its completion date as March 1950, its management division as the Yamaguchi Prefecture Civil Engineering and Construction Department, and its contact point as the Kotogawa Dam Management Office. The official description mentions Act Village Ono, an experiential learning facility located in the center of Ono Lake, which is used and introduced as a place for E-boat competitions and a migratory site for mandarin ducks. The ghost of the girl, the entity chasing cars, and the circumstances surrounding the disappearance of the old tunnel are not mentioned on the official page.

• Kotogawa Dam, Yamaguchi Prefecture(Confirmed on 2026-09-28) — It is listed as "Kotogawa Dam (Onoko Lake)," with its location in Kida, Ube City, Yamaguchi Prefecture, its completion date in March 1950, and its management division as the Yamaguchi Prefectural Department of Civil Engineering and Construction.

Points of agreement/contradictions

The name Ono Lake, the location within Ube City, and the relationship between the lake and the Kotogawa Dam are supported by the prefecture's official "Kotogawa Dam (Ono Lake)" and location information. However, the ghost of a young girl standing on the lake's surface, the upper body chasing a car, and the circumstances under which the old tunnel was turned into a cut-and-cover tunnel cannot be confirmed from the official documents obtained. The facility's response is supported, but the details of the supernatural occurrences and the tunnel remain unconfirmed, so it is considered a partial agreement.

The rumored atomic claim	Matching results	reason	Corresponding documents
Ono Lake is described as "a lake (pond) or dam located in Ube City, Yamaguchi Prefecture."	support	The Yamaguchi Prefecture official website lists the dam as "Kotogawa Dam (Ono Lake)," stating its location as Kida, Ube City, and the managing body as the Prefectural Department of Civil Engineering and Construction, thus supporting the information provided.	Kotogawa Dam, Yamaguchi Prefecture
A girl's ghost appears	Unconfirmed	Official documents describe the facilities and natural environment of Lake Ono, but they do not record any appearances of the girl's ghost or sightings on the lake's surface.	No official data available for direct comparison.
The tunnel has now disappeared, replaced by a cut-and-cover section.	Unconfirmed	The official overview of the Kotogawa Dam that was obtained does not mention the disappearance of the old tunnel or the history of its conversion into a cut-and-cover tunnel, and the road history cannot be determined based solely on the description on the rumor page.	No official data available for direct comparison.

Alternative interpretation

The official documents describe the use of the water surface, the experiential learning facilities, and the surrounding nature, explaining the waterside setting, which changes depending on the time of day and weather. The reflections on the lake surface, car lights, and the perspective of the dark road may overlap with the rumored descriptions, but this is a general alternative interpretation and does not definitively determine the cause of individual experiences.

Scope and limitations of the investigation

The prefectural government's official website deals with the dam's purpose, scale, facility use, and natural environment, but it is not a record of events that verifies the high number of suicides, the sighting of the girl, and the alteration of the old tunnel mentioned on the rumor page. The relative locations of the Ono Tunnel and the supposedly vanished old tunnel, the origin of the rumor, and the authenticity of the individual videos were not included in the scope of this direct acquisition.

Verification results: Partial match

The information that Lake Ono is a lake formed by the Koto River Dam and located in Ube City corresponds to official documents from Yamaguchi Prefecture. On the other hand, the ghost of the girl, the entity chasing the car, and the disappearance of the old tunnel cannot be confirmed in independent official documents. Since confirmed facts about the facility and unconfirmed descriptions of the supernatural coexist, it is judged to be a partial match.

Document Quality Score

Source transparency	28/30	The prefectural government's official individual dam page shows its relationship to Lake Ono (alternative name), location, completion year, and administrator, and also allows you to check the source of the rumors, including the update date and the scope of the claims.
Historical and spatial context	22/25	The book includes information on the dam's completion in 1950, its purpose, the Act Village Onoya boat race, and mandarin ducks, providing a detailed history of waterfront use.
Safety information	17/20	Official documents reveal the existence of controlled bodies of water and experiential learning facilities, and combined with the warning against unauthorized entry on the rumors page, it is difficult to underestimate the dangers of the waterfront.
Newness of information	13/15	The rumor page was updated in 2023, and the official Kotogawa Dam overview was updated in 2022, so there are up-to-date materials available for comparing basic facility information.
Transparency of the source of rumors	7/10	While the descriptions of the girl and the tunnel are detailed, the original publication date, verifiable eyewitness accounts, and links to case files cannot be confirmed from the published page.
total	87/100	This is the overall quality of the materials. It does not represent the degree of truthfulness or danger associated with the supernatural phenomena.

Safety information and maps

Lake Ono is a lake under the management of the Koto River Dam, and official documents introduce its use for environmental education and boating competitions, but they do not permit free nighttime exploration. There are dangers on the water surface, dark roads, and management facilities, so avoid restricted areas, do not enter the site to verify rumors, and rely only on publicly available documents and official guides.

Check the area around Lake Ono on Google Maps.

3rd Place: Sugano Dam | Partial Match (85 points)

The rumored details

The June 13, 2024 update page of the National Haunted Map describes the Sugano Dam as a place where "a female ghost appears" and "figures can be seen," explaining that it is a multi-purpose dam located in Nakasukita, Shunan City, Yamaguchi Prefecture, completed in March 1966. Furthermore, it mentions that an old village was submerged in the dam lake, that there are many suicides there, and that in December 2003, a mother attempted a murder-suicide. It also states that a female ghost and a dark figure have been sighted in Nakanoshima Park. At the end of the page, there is a dated quote attributed to the Yomiuri Shimbun, but here we will treat it as the claims presented by the source.

Source of the rumor and date of verification

The source of the rumor is the Sugano Dam direct page on the National Haunted Map, and the last update date at the time of verification was June 13, 2024. Although the page contains a Yomiuri Shimbun headline and a quote from December 10, 2003, the original newspaper article was not directly obtained during this investigation. The sources of the paranormal descriptions, incident descriptions, and quotes have been separated and recorded as examples of secondary publication/original source unconfirmed.

• Nationwide Haunted Places Map: "Sugano Dam | Sugano Dam - A Haunted Spot in Yamaguchi Prefecture"(Verification Date: 2026-09-28) — The post mentions "a female ghost appearing" and "a human figure being seen," and includes information about a multi-purpose dam completed in 1966, a 2003 incident, and eyewitness accounts from the surrounding park in the same rumor description.

Things that could be confirmed from official and primary source materials

The Yamaguchi Prefecture page for "Sugano Dam" refers to the Sugano Dam as Sugano Lake, stating its location as Nakasukita, Shunan City, Yamaguchi Prefecture, its water system as the Nishiki River system, and its completion date as March 1966. Its purpose is flood control, industrial water supply, municipal water supply, and power generation, its management is handled by the Yamaguchi Prefecture Civil Engineering and Construction Department, and its contact is the Yamaguchi Prefecture Sugano Dam Management Office. While it also lists public toilets and a camping area as park facilities, it does not mention ghosts, the circumstances surrounding the submersion of the settlement, suicides, or the 2003 incident in its official summary.

• Sugano Dam, Yamaguchi Prefecture(Confirmed on 2026-09-28) — Regarding the Sugano Dam (Sugano Lake), the location is listed as Nakasukita, Shunan City, Yamaguchi Prefecture, the purpose as flood control, industrial water supply, water supply, and power generation, the completion date as March 1966, and the management division as the Yamaguchi Prefectural Department of Civil Engineering and Construction.

Points of agreement/contradictions

The completion date of March 1966, the location in Nakasukita, Shunan City, and the fact that it is a multi-purpose dam correspond to the description on the rumor page and the official prefectural overview. Conversely, the descriptions of a female ghost or figure, the submersion of an old village, the assessment of a high number of suicides, and the 2003 incident cannot be confirmed on the official page obtained this time. Since the original source of the quote attributed to the Yomiuri Shimbun has not been obtained, the text from the source has not been elevated to factual confirmation, and the supported facility information and the unconfirmed incidents and strange occurrences have been listed together as partial matches.

The rumored atomic claim	Matching results	reason	Corresponding documents
A multipurpose dam located in Nakasukita, Shunan City, Yamaguchi Prefecture, completed in March 1966.	support	The prefectural government's official website lists the completion date as March 1966, the location as Nakasukita, Shunan City, and lists the purposes of flood control, industrial water supply, water supply, and power generation, thus supporting the material claims.	Sugano Dam, Yamaguchi Prefecture
A female ghost appears	Unconfirmed	The official overview describes the dam's purpose, size, management classification, and park facilities, but it does not include any descriptions confirming the appearance of a female ghost or other human figures.	No official data available for direct comparison.
In December 2003, there was an incident in which the mother attempted a murder-suicide.	Unconfirmed	The rumor page includes a quote attributed to the Yomiuri Shimbun, but the original source has not been directly verified, and the official prefectural dam overview obtained does not contain any record of the incident, therefore the facts of the incident cannot be confirmed.	No official data available for direct comparison.

Alternative interpretation

The environment—a dam lake, a dam embankment, mountain trails at night, and a campsite—easily creates an unsettling impression due to the lack of sound and lighting. If we first examine the functions of the facility as a flood control and water utilization facility, as well as its use as a park, as shown in official documents, we can consider the management environment of the waterside separately from the paranormal explanations, but there are no records that definitively determine the cause of the impression.

Scope and limitations of the investigation

The official overview is a document that shows the dam's specifications and management information, and is not a comprehensive record of accidents and incidents, a history of the relocation of the old settlement, or a verification document of eyewitness accounts. The original Yomiuri Shimbun article cited by the source, the official records of the car fall and the 2003 incident, and individual experiences at Nakanoshima Park have not been directly verified, so unverified information will not be considered inconsistent.

Verification results: Partial match

The material claims regarding the location, completion date, and purpose of the Sugano Dam correspond to those on the prefectural government's official website. However, claims about ghosts, shadows, submerged settlements, a high suicide rate, and the 2003 incident are not supported by the official documents, and the newspaper citations lack source verification. Since only some of the specific claims are supported, it is judged as a partial agreement.

Document Quality Score

Source transparency	28/30	The prefectural government's official specifications page specifies the location, purpose, completion date, and administrator, and also indicates the source of the rumors and the source of the incident citation, making the starting point for comparison clear.
Historical and spatial context	22/25	The Nishikigawa River system, completed in 1966, is officially designated as a dam with multi-purpose use and a camping area, allowing us to trace the temporal and spatial background of the facility.
Safety information	17/20	The park facilities and management divisions are listed on the official website, and restrictions on nighttime use and water surface use can also be found in other official prefectural usage regulations, making it easier to concisely provide safety information.
Newness of information	11/15	While the rumor page was updated in 2024, the official summaries of individual dams were updated in 2022. Therefore, we evaluated them not based on their recency as incident records, but as a basis for verifying the facilities.
Transparency of the source of rumors	7/10	While it includes citations of the date of the incident and the name of the newspaper, it is not possible to directly obtain the original newspaper article, making it necessary to distinguish between the primary nature of the paranormal descriptions and the accident information.
total	85/100	This is the overall quality of the materials. It does not represent the degree of truthfulness or danger associated with the supernatural phenomena.

Safety information and maps

Sugano Dam is managed by the Prefectural Department of Civil Engineering and Construction, and its official overview lists public toilets and a camping area. Another official prefectural usage rule restricts the use of the lake surface and swimming from sunset to sunrise, so it is necessary to avoid approaching the waterfront at night, abide by the rules regarding the managed area, dam body, and lake surface, and not enter for the purpose of verifying rumors.

Check the area around Sugano Dam on Google Maps.

What I learned by crossing locations

What the three locations have in common is that the rumor pages place information about the existence of the lakes and dams together with descriptions of paranormal activity in the same paragraph. Toyoda Lake is related to the Koya River Dam and its use as a park, Ono Lake is related to the Koto River Dam by sharing the same name and its use for environmental education, and Sugano Dam's completion date and purpose are specified in official documents. On the other hand, ghost sightings, spirits chasing cars, black figures, and causal relationships in incidents are not covered in the official summaries. The important difference across the three locations is not to confuse the confirmation of names, locations, and facility uses with the evidence for paranormal phenomena and accidents.

summary

In all three locations, the place names indicated by the source of the rumors were matched with the regional information of the dams and lakes confirmed in official documents from Yamaguchi Prefecture. However, the official documents did not confirm the claims of female or girl ghosts, shadowy figures, nighttime anomalies, or past incidents. At Toyoda Lake and Ono Lake, the identification of the facilities was supported, but the paranormal activity remained unconfirmed. At Sugano Dam, the correspondence between the completion date and location was confirmed, but the verification of the original source of the incidents and paranormal phenomena was withheld. Readers can only verify facility information; further documents are needed to confirm the origin of the rumors and the existence of the phenomena.

FAQ

Does the partial matching on this page confirm the existence of ghosts?

No. Partial matches indicate a situation where some specific claims, such as place names or facility descriptions, correspond to official documents, while claims of spirits or anomalies remain unconfirmed. This classification does not certify the existence of supernatural phenomena.

If a rumor isn't mentioned in official documents, is that considered a discrepancy?

We do not consider something a discrepancy simply because it is not listed. A discrepancy is considered to exist only when other facts directly contradict the subject, time period, or purpose, and if there is insufficient comparative data, it will be classified as unconfirmed, partially matching, or unmeasurable.

What location does the map coordinate represent?

Toyoda Lake and Ono Lake indicate the representative locations of the lakes, while Sugano Dam indicates the location of the dam itself. The embedded and search links use the same latitude, longitude, and official location names, but do not guarantee access to the actual sites or safety.

Is it okay if I go to the location at night to verify the rumors?

Avoid nighttime visits and trespassing into restricted areas. Dams and lakes are subject to management regulations, and the waterfront can be unstable in terms of footing and visibility. This article is a compilation of publicly available information and does not encourage exploration.