Matsuri Guide

Name in Japanese and English

• 老神温泉赤城神社例祭 大蛇まつり
• Oigami Onsen Daija Matsuri, the “Great Snake Festival” (annual festival of Akagi Shrine)

History

The Daija Matsuri（大蛇まつり, daija matsuri）is the major ritual event of 老神温泉（おいがみおんせん, Oigami Onsen）in Numata (沼田市, Numata-shi, Gunma Prefecture 群馬県, Gunma-ken). It is held as the 例祭（れいさい, reisai, “annual festival”）of Akagi Shrine（赤城神社, Akagi Jinja）, located in the heart of the hot spring town.

The festival is rooted in the legend of the opening of the springs（開湯伝説, kaitō densetsu）: the kami（神, kami）of Mount Akagi (赤城山, Akagi-yama), taking the form of a great serpent（大蛇, daija）, is said to have fought his rival, been wounded, and then caused the hot water to spring forth by pulling out the arrow lodged in his body. This story explains the idea of the protective serpent deity（守り神, mamori-gami）and nourishes the symbolism of the matsuri: gratitude for the onsen, prayers for the safety (無事故, mu-jiko) and health (健康, kenkō) of visitors.

Over time, the celebration has become a “matsuri-show” centered on mikoshi（神輿, mikoshi）in the shape of serpents, carried through the main street of the onsen town (温泉街, onsen-gai). A famous feature: during the Years of the Serpent（巳年, mi-doshi, every 12 years）, a giant mikoshi approximately 108.22m long can be brought out for a special procession, becoming a strong symbol of local pride.

Location and Date of the Event

• Location: Akagi Shrine（赤城神社, Akagi Jinja）and onsen streets（老神温泉街, Oigami onsen-gai）at Oigami Onsen.
• Address: 〒378-0322 群馬県沼田市利根町老神607-1（around Oigami Onsen / near Tone Tourism Hall）
  Romanization: 607-1 Oigami, Tonemachi, Numata-shi, Gunma 378-0322.
• Access: from JR 沼田駅（ぬまたえき, Numata-eki）, bus to 老神温泉（おいがみおんせん, Oigami Onsen）(about 40–50 minutes), then a short walk depending on the stop. By car: from 沼田IC（ぬまたインター, Numata IC, Kan-Etsu Expressway 関越道 Kan-Etsu-dō）, about 25 minutes depending on traffic.
• Date: every year on the 2nd Friday and 2nd Saturday of May（5月第2金・土, gogatsu dai-ni kin/do）. Recent example: May 9–10, 2025.

Schedule

The matsuri takes place over 2 days. The atmosphere alternates between Shinto ceremonies (神事, shinji) at the shrine and festive moments in the streets. Worshippers and visitors come seeking protection (厄除け, yaku-yoke), good health, and “safe travels” in a broad sense: a safe, welcoming hot spring resort blessed by the protective serpent.

The ritual framework opens with the annual festival of the shrine (赤城神社例大祭, Akagi Jinja rei-taïsai). A well-identified highlight of the program is the ceremony of guarding the sacred waters（御神湯守の儀, goshinyu-mori no gi）, conducted in connection with the onsen establishments. Then come the processions (渡御, togyō) of the serpent mikoshi (蛇みこし, hebi mikoshi): depending on the schedule, one can see a children’s mikoshi (子ども…みこし, kodomo … mikoshi) and, in the evening, the energetic march of the young carriers’ mikoshi（若衆みこし, wakashū mikoshi）throughout the onsen street.

The “wow” highlight remains the procession of the great serpent（大蛇みこし, daija mikoshi）which literally undulates through the crowd. During the Years of the Serpent（巳年, mi-doshi）, a giant version about 108.22m long can be brought out for a special procession, with impressive logistics and a higher density of spectators than usual.

Practical Tips

Photos

To capture the “undulating serpent” effect, position yourself on a slightly curved section of street or at an intersection to get depth. For the liveliest moments: aim for the evening (young carriers’ mikoshi) for energy and expressions, and the mid-afternoon for clearer images (less contrast). Bring a versatile zoom lens (24–70mm) plus a short telephoto to isolate carriers and details (serpent heads, ropes, happi coats 法被).

Weather

Early May at Oigami Onsen can have mild days but cool evenings in the valley. Dress in layers (light jacket + warm layer), and favor stable shoes (lots of standing, sidewalks, and traffic areas). In case of rain, a poncho protects better in crowds than an umbrella.

Transport

Buses from Numata (沼田, Numata) can fill up during the festival, especially in late afternoon slots. If you come for the evening, plan your trip and check the last return. By car, arrive early to park without stress: parking lots near central points fill quickly in highly publicized years (notably 巳年).

Visitor Tips

For a comfortable experience: choose a fixed spot and let the procession come to you, rather than “chasing” the mikoshi. If you stay overnight, you can combine with a walk to 吹割の滝（ふきわれのたき, Fukiware-no-taki）in the area, and return for the evening. A simple useful phrase: がんばって！（ganbatte, “good luck!”）to the carriers, always well received.

What to Bring

Cash (for small purchases, stalls), portable charger, poncho, towel (onsen), jacket for the evening, hand warmers (カイロ, kairo) if you get cold, and a small bag to protect your photo equipment from splashes and rain.

Sources & References

• 沼田市：老神温泉大蛇まつり（イベント情報・スケジュール）

  Municipal page: dates, detailed program (rituals, processions), locations and practical information.

• 老神温泉（公式）：老神（おいがみ）のイベント情報

  Official destination site: announcements, logistical information (parking, routes, news around the matsuri).

• Visit Gunma: Oigami Onsen Daija (Large Snake) Festival

  Tourism office (Gunma): summary, address, access, period, and tips for organizing the visit.

• Gunma Kankō: Experience the heat of the Oigami Onsen Daija Matsuri with a 108m snake dancing!

  In-depth article: context, onsen legend, role of Akagi Shrine, and focus on the 2025 edition.