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Nijumurago: Ojiya and Yamakoshi, Niigata

By the koi.wiki editorial team · Updated

Key facts: Nijumurago (二十村郷, "twenty villages") is the historical name for the snowbound, terraced farming district spanning present-day Ojiya and Yamakoshi in Niigata Prefecture, where the systematic breeding of ornamental koi began in the 1820s.[1][2]
Nijumurago (二十村郷) refers to a cluster of mountain villages in the Chuetsu region of Niigata Prefecture, an area later divided between the eastern part of Ojiya City and the Yamakoshi area of Nagaoka City.[2] The region was isolated by heavy winter snowfall, sometimes described as a “landlocked island,” and farmers kept common carp through the winter months as a food source.[2] The emergence of color and pattern mutations among these food carp is considered the beginning of nishikigoi (錦鯉).[2][5]According to Wikipedia, systematic breeding of ornamental Amur carp began in the 1820s in Nijumurago.[1] Carp had been farmed for food in the area, and by 1781 at the latest they were also kept in terraced ponds near terraced rice paddies; when drought dried the ponds that year, the carp are said to have taken refuge in ponds on the grounds of Senryu Shrine in Higashiyama Village and Juni Shrine in Higashitakezawa Village.[1] During the Bunka and Bunsei eras (1804–1830), villagers bred red and white koi in addition to black koi, and crossed them to produce red-and-white colored koi, continuing to refine the fish afterward.[1]

Geography and climate

Ojiya is an inland city at the southern end of the Echigo Plain in central Niigata Prefecture, through which the Shinano River flows; the area has a humid subtropical climate with very heavy snow in winter.[6] Yamakoshi, once a separate village in Koshi District, lay in the same mountainous, snow-bound district and is noted for terraced rice paddies and bullfighting (ja:牛の角突き) as local attractions.[7] Japanese-language sources describe the wider area straddling Ojiya and the Yamakoshi district of Nagaoka as having a landscape of terraced paddies and terraced ponds, recognized as a Japan Heritage agricultural system built around rice farming and carp culture adapted to heavy snow.[8]

Origins of nishikigoi in the twenty villages

According to the All Japan Nishikigoi Promotion Association (JNPA), nishikigoi date back more than 200 years to the late Edo period, originating in the Nijumurago area described above.[2][9] A related account by Shinkokai USA likewise locates the first nishikigoi offspring from magoi (common carp) in this area, which was noted for being rich in magoi stock.[10] Ojiya City’s own tourism page states that nishikigoi first appeared in the first half of the 19th century, during the Bunka and Bunsei eras, when color mutations ("kawarimono") arose among food carp kept in Nijumurago, in what is now part of Ojiya and Nagaoka.[3] A dealer account, Kodama Koi Farm, also traces the first colored offspring of magoi carp to the Yamakoshi and Ojiya area, stating that residents began selective breeding as they noticed the color changes.[11] Sources describing individual varieties such as Goshiki, Shusui, and ghost koi repeat the same Nijumurago origin story for the broader development of ornamental carp.[12][13][14]Ojiya City states that nishikigoi are now produced in the city at a rate representing about 45 percent of the prefecture's output, and that the fish are nicknamed “swimming jewels” for the color developed using the region's clear mountain water and traditional techniques.[3] JNPA notes that national recognition grew after the 1914 Tokyo Taisho Exposition in Ueno Park, where about twenty nishikigoi (then called "kawarigoi") were exhibited and won a silver medal during a four-month event that drew roughly 7.5 million visitors; Crown Prince Hirohito, later Emperor Showa, was reportedly fond of the fish, which were subsequently kept at the Imperial Palace.[2] JNPA also notes that in 2022 the names and definitions of 21 varieties were standardized under the Japanese Agricultural Standards, and that more than 150 varieties are now recognized worldwide, a count that differs from the comparison frequently cited for varieties such as Kohaku and Showa Sanshoku.[2]

Yamakoshi: terraced ponds and village life

Yamakoshi, now part of Nagaoka City, was a mountain village known for bullfighting, rice terraces, and koi farming.[7] The Japanese-language account of the former village states that from the 1970s, folklorist Miyamoto Tsuneichi assisted with regional promotion, marketing the forested hillside terraces, paddies, nishikigoi farming, and bullfighting as symbols of an older Japanese rural landscape.[15] The same source records that a koi auction facility was completed in the village in 1964 and a comprehensive nishikigoi center in 1978, and that the local economy, alongside terraced rice cultivation, shifted over the 1960s from carp raised as a side occupation in rice paddies toward specialized koi farming with a growing number of dedicated ponds.[15] Nishikigoi farming is listed among Yamakoshi's notable local industries together with beef cattle production.[15]Yamakoshi merged into the city of Nagaoka in 2005, alongside several other towns.[7] The village had been struck by the 2004 Chuetsu earthquake, which caused extensive damage in the Niigata region, including at least 5 deaths recorded in Yamakoshi and widespread landslide and housing damage across Ojiya, Nagaoka, and neighboring areas; residents of Yamakoshi were evacuated and the village was largely cut off from road access, with most of its roughly 2,200 residents airlifted or evacuated to Nagaoka.[4]

Ojiya Nishikigoi no Sato

Ojiya operates a municipal facility known as Nishikigoi no Sato (錦鯉の里, "Nishikigoi Village"), combining a park with ponds, waterfalls, and bridges where visitors can view and feed koi, alongside an exhibition hall with displays on nishikigoi history, varieties, and husbandry, plus a separate viewing pool for prize specimens.[3] The facility is open from 9:00 a.m. to 5:00 p.m. and is closed from December 29 to January 3.[3] As of the rate revision effective April 1, 2026, individual admission is 550 yen for adults and 330 yen for elementary and junior high school students, with group rates (20 or more) of 440 yen and 270 yen respectively; an annual pass for Ojiya City residents is 1,100 yen; children not yet in elementary school are admitted free.[3] The address is 1-8-22 Jonai, Ojiya City, Niigata Prefecture, reachable by car in about five minutes from JR Ojiya Station or the Ojiya Interchange on the Kan-etsu Expressway, or by local bus and an on-demand shuttle service.[3]According to the affiliated site Ojiya Nishikigoi no Sato, the koi on display are purchased from producers within Ojiya City and range from 3 to 30 years of age and from 50 centimeters (about 1.6 ft) up to just over 1 meter (3.3 ft) in length, with around 40 representative varieties kept, including Koromo, Kinginrin, Kujaku, Kohaku, Yamabuki Ogon, Utsurimono, Showa Sanshoku, Asagi, and Tancho-patterned fish.[16]

Shows and events in Ojiya

Ojiya holds nishikigoi judging events each spring and autumn: a spring event for overwintered "tate-goi" (立て鯉, fish kept standing through winter) and an autumn event, the Niigata Prefecture Nishikigoi Competition, held as part of the National Agriculture, Forestry and Fisheries Festival and drawing enthusiasts from around the country.[3] A municipal report on the 65th Niigata Prefecture Nishikigoi Competition, held over two days in November at the Ojiya City Gymnasium Community Plaza, recorded 469 koi entered by prefectural producers and 1,010 visitors across the two-day event; the Minister of Agriculture, Forestry and Fisheries Award for overall grand champion went to a Kohaku, while a 102-centimeter (about 3.3 ft) chagoi won a "jumbo" award for size, and the overall winning producer was Dainichi Yoshikigoi Farm.[17] JNPA, which is headquartered at a nishikigoi promotion center in Hiu, Ojiya City, separately lists the International Junior Koi Show as being held at the Ojiya City Gymnasium Community Plaza.[18][19] Further information on judging standards and show categories appears on the pages for how koi are judged and the Niigata Nishikigoi Show.

Common questions

What does Nijumurago mean?
Nijumurago (二十村郷, "twenty villages") is the historical name for a snowbound mountain district spanning what is now eastern Ojiya City and the Yamakoshi area of Nagaoka City in Niigata Prefecture, where ornamental koi breeding is said to have begun.[2][1]
Why did nishikigoi originate in this area?
Farmers in the isolated, heavy-snow region kept common carp through the winter as a food source, and color and pattern mutations that appeared among these fish were selectively bred into what became nishikigoi.[2][11]
What can visitors see at Ojiya Nishikigoi no Sato?
The facility combines an outdoor park with koi ponds, waterfalls and bridges where visitors can feed the fish, an exhibition hall covering nishikigoi history and varieties, and a viewing pool of prize specimens, with roughly 40 varieties on display.[3][16]
How did the 2004 earthquake affect Yamakoshi?
The 2004 Chuetsu earthquake caused extensive landslide damage and road closures that isolated Yamakoshi, leading to evacuation of nearly all its roughly 2,200 residents to Nagaoka; at least five deaths in the village were linked to the quake.[4]
Is Ojiya still a center of nishikigoi production?
Ojiya City states that it produces about 45 percent of Niigata Prefecture's nishikigoi output and is widely associated with the fish both domestically and internationally.[3]

References

  1. ^ Koi (Wikipedia). Wikipedia. en.wikipedia.org/wiki/Nishikigoi. Retrieved November 2026.
  2. ^ The Birth and History of Nishikigoi - All Japan Nishikigoi Promotion Association. All Japan Nishikigoi Promotion Association. jnpa.info/en/nishikigoi/history/. Retrieved November 2026.
  3. ^ 錦鯉の里 - 小千谷市ホームページ. Ojiya City. city.ojiya.niigata.jp/site/kanko/nishikigoinosato.html. Retrieved November 2026.
  4. ^ 2004 Chūetsu earthquake (Wikipedia). Wikipedia. en.wikipedia.org/wiki/2004_Chūetsu_earthquake. Retrieved November 2026.
  5. ^ Koi (Wikipedia). Wikipedia. en.wikipedia.org/wiki/Koi. Retrieved November 2026.
  6. ^ Ojiya, Niigata (Wikipedia). Wikipedia. en.wikipedia.org/wiki/Ojiya,_Niigata. Retrieved November 2026.
  7. ^ Yamakoshi, Niigata (Wikipedia). Wikipedia. en.wikipedia.org/wiki/Yamakoshi,_Niigata. Retrieved November 2026.
  8. ^ 小千谷市 (Wikipedia). Wikipedia (Japanese). ja.wikipedia.org/wiki/小千谷市. Retrieved November 2026.
  9. ^ Introduction of Nishikigoi - All Japan Nishikigoi Promotion Association. All Japan Nishikigoi Promotion Association. jnpa.info/en/nishikigoi/. Retrieved November 2026.
  10. ^ Introduction of Nishikigoi - Shinkokai USA Official Website. Shinkokai USA (JNPA). shinkokaiusa.com/introduction-of-nishikigoi. Retrieved November 2026.
  11. ^ What is a Nishikigoi? - Koi Fish History Explained and Meaning. Kodama Koi Farm (koi dealer). kodamakoifarm.com/what-is-nishikigoi-history-meaning/. Retrieved November 2026.
  12. ^ Koi (Wikipedia). Wikipedia. en.wikipedia.org/wiki/Goshiki. Retrieved November 2026.
  13. ^ Koi (Wikipedia). Wikipedia. en.wikipedia.org/wiki/Shusui. Retrieved November 2026.
  14. ^ Koi (Wikipedia). Wikipedia. en.wikipedia.org/wiki/Ghost_koi. Retrieved November 2026.
  15. ^ 山古志村 (Wikipedia). Wikipedia (Japanese). ja.wikipedia.org/wiki/山古志村. Retrieved November 2026.
  16. ^ 小千谷市 錦鯉の里-つちかわれた伝統と地場産業を明日へ伝える総合産業会館サンプラザ. Ojiya Nishikigoi no Sato. nishikigoinosato.jp/appreciation.html. Retrieved November 2026.
  17. ^ 第65回新潟県錦鯉品評会が開催されました（11月8日・9日） - 小千谷市ホームページ. Ojiya City. city.ojiya.niigata.jp/soshiki/kikakuseisaku/nishikigoi202511.html. Retrieved November 2026.
  18. ^ Message from the President / Overview of the organization - All Japan Nishikigoi Promotion Association. All Japan Nishikigoi Promotion Association. jnpa.info/en/about/profile/. Retrieved November 2026.
  19. ^ Schedule of the Nishikigoi Show - All Japan Nishikigoi Promotion Association. All Japan Nishikigoi Promotion Association. jnpa.info/en/show/schedule/. Retrieved November 2026.