Matsuri Guide

Name in Japanese and English

• 大山祇神社例大祭・後宮祭
• The Grand Festival (Reitaisai) and the Closing Rite (Atomiya-sai) of Ōyamazumi Shrine

History

Ōyamazumi Jinja（大山祇神社）is one of the major shrines of the Shimanami Kaidō（しまなみ海道） region on the island of Ōmishima（大三島）. Its main annual observance is the reitaisai（例大祭）, held according to the lunar calendar（旧暦, kyūreki）. The shrine states that this date commemorates the shrine’s establishment (transfer) to its current site in Yōrō 3（養老3年, 719）, making this festival both a religious and an identity-defining celebration for the island.

In local tradition, these three days are called the haru no taisai（春の大祭, “grand spring festival”): on the eve, the migokoromigae mitoake-sai（御更衣御戸開祭, a rite of “changing vestments” and ritual opening) is held, then the central day features the reitaisai（例大祭）, and the following day concludes with the atomiya-sai（後宮祭, a closing/report rite). The festival is also known for its large market, the Mishima-ichi（三島市）, which draws visitors from the island and beyond.

Event location and date

• Location: Ōyamazumi Jinja（大山祇神社）.
• Address: 〒794-1393 愛媛県今治市大三島町宮浦3327（3327 Miyaura, Ōmishima-chō, Imabari-shi, Ehime）.
• Access: bus to the Ōyamazumi Jinja-mae（大山祇神社前）stop, then 1–2 min on foot; by car via the Shimanami Kaidō（しまなみ海道）, exit at Ōmishima IC（大三島IC）and drive about 10–15 min. Free municipal parking is available nearby (depending on season/crowds).
• Date: the 22nd and 23rd of the 4th lunar month（旧暦4月22日・4月23日）, with the 御更衣御戸開祭 rite held on the eve.
• Date type: variable—the days are fixed on the lunar calendar, but shift each year on the Gregorian calendar (often late May or June).

Schedule

The festival unfolds over three days and combines solemn rites, collective prayers, and lively community atmosphere. People come to pray for protection, peace, prosperity, and the safety of the land, in a setting that feels both “grand shrine” and warmly “local”: families, residents, and travelers passing through the Shimanami Kaidō.

On the eve, the migokoromigae mitoake-sai（御更衣御戸開祭）symbolizes ritual “renewal” (offering sacred vestments) and the opening of ritual spaces. The next day, the festival’s core is the reitaisai（例大祭）: the main ceremony (often announced at 10:00) with prayers and offerings. Finally, the atomiya-sai（後宮祭）serves as the closing: the successful completion of the grand rite is “reported” to the kami (神, kami), and the cycle is brought to an end.

For atmosphere, the highlight is the Mishima-ichi（三島市）: many stalls (屋台, yatai) line up, and the approach to the shrine becomes a long corridor of stands—perfect for snacking, picking up small souvenirs, and feeling an early-summer vibe on the island.

Practical tips

Photos

For lively atmosphere, aim for late afternoon and early evening: the stalls read better, and the crowd gives a sense of scale. For the shrine itself, arriving early in the morning also works well for calmer images (torii, paths, buildings) before peak crowds. A wide-angle helps capture the depth of the approach, and a standard lens is ideal for stall scenes. In crowds, keep your bag in front and avoid changing lenses in the middle of the flow.

Weather

On the Gregorian calendar, the festival often falls in late May or June: mild to warm days, possible humidity, and a chance of showers as the rainy season (梅雨, tsuyu) approaches. Bring light layers, and comfortable shoes (lots of walking and standing).

Transport

If you are doing the Shimanami Kaidō, driving access is straightforward via Ōmishima IC（大三島IC）. By public transport, take a bus to Ōyamazumi Jinja-mae（大山祇神社前）. On festival days, plan to arrive early: nearby parking and some buses can be more crowded.

Visitor tips

If your goal is the ceremony, scout in advance where to stand without blocking passage. For the market, the best balance is often before the peak (early evening). A useful phrase if you are asking for a stop or location: “大山祇神社はどこですか？” (Ōyamazumi jinja wa doko desu ka?: “Where is Ōyamazumi Shrine?”).

What to bring

Cash (many stalls), power bank, water, wipes, insect repellent, poncho (often more practical than an umbrella in crowds), and a light bag if you buy omamori（お守り, omamori）or souvenirs.

Sources & References

• 祭礼・催し（例大祭・後宮祭の説明, 【公式】大山祇神社）

  Official overview: origin (遷座, meaning of the rite), the 3-day sequence (御更衣御戸開祭・例大祭・後宮祭), and indicative times.

• 大山祇神社例大祭・後宮祭（今治市イベント情報）

  Municipal listing: description, address, parking, and the dates announced for the year of the last update (e.g., 2025).

• アクセス（【公式】大山祇神社）

  Official address and practical information (contact, access).

• 5月のイベント情報（2022, 今治地方観光協会）

  Local calendar mentioning the 2022 edition (22–23 May).